diff --git a/packages/ui/src/components/sections/openchamber/VoiceSettings.tsx b/packages/ui/src/components/sections/openchamber/VoiceSettings.tsx
index 8d3a1ac3..9abfeffe 100644
--- a/packages/ui/src/components/sections/openchamber/VoiceSettings.tsx
+++ b/packages/ui/src/components/sections/openchamber/VoiceSettings.tsx
@@ -71,6 +71,7 @@ const LOCAL_STT_MODELS = [
 
 interface DictationModelState {
     id: string;
+    description?: string;
     installed: boolean;
     downloading: boolean;
     downloadProgress: number | null;
@@ -288,10 +289,32 @@ const KOKORO_VOICE_OPTIONS = [
 
 const LOCAL_TTS_MODEL_ID = 'kokoro-en-v0_19';
 
-const LocalTtsModelStatus = () => {
-    const { t } = useI18n();
-    const [model, setModel] = useState<DictationModelState | null>(null);
-    const [requesting, setRequesting] = useState(false);
+const KOKORO_MULTI_LANG_MODEL_ID = 'kokoro-multi-lang-v1_1';
+// A few named speakers out of the 103 in the Chinese/English Kokoro build.
+const KOKORO_MULTI_LANG_VOICE_OPTIONS = [
+    { id: 0, label: 'Maple (af)' },
+    { id: 1, label: 'Sol (af)' },
+    { id: 2, label: 'Vale (bf)' },
+    { id: 3, label: 'Xiaoxiao (zf)' },
+    { id: 58, label: 'Yunxi (zm)' },
+];
+
+interface LocalTtsVoiceOption {
+    modelId: string;
+    speakerId: number;
+    label: string;
+}
+
+const localTtsVoiceKey = (modelId: string, speakerId: number): string => `${modelId}:${speakerId}`;
+
+/**
+ * Local TTS models as the server reports them, plus the actions Settings
+ * offers on them. Shared by the model list and the voice picker so both see
+ * the same install state.
+ */
+const useLocalTtsModels = () => {
+    const [models, setModels] = useState<DictationModelState[]>([]);
+    const [requestingId, setRequestingId] = useState<string | null>(null);
 
     const refresh = useCallback(async () => {
         try {
@@ -300,11 +323,8 @@ const LocalTtsModelStatus = () => {
                 return;
             }
             const data = await response.json();
-            const entry = Array.isArray(data?.ttsModels)
-                ? data.ttsModels.find((m: DictationModelState) => m.id === LOCAL_TTS_MODEL_ID)
-                : null;
-            if (entry) {
-                setModel(entry);
+            if (Array.isArray(data?.ttsModels)) {
+                setModels(data.ttsModels);
             }
         } catch {
             // Display-only status; keep the previous state on fetch failure.
@@ -315,81 +335,118 @@ const LocalTtsModelStatus = () => {
         void refresh();
     }, [refresh]);
 
+    const anyDownloading = models.some((model) => model.downloading);
     useEffect(() => {
-        if (!model?.downloading) {
+        if (!anyDownloading) {
             return;
         }
         const interval = setInterval(() => {
             void refresh();
         }, 2000);
         return () => clearInterval(interval);
-    }, [model?.downloading, refresh]);
+    }, [anyDownloading, refresh]);
 
-    const request = async (method: 'POST' | 'DELETE') => {
-        setRequesting(true);
+    const request = useCallback(async (modelId: string, method: 'POST' | 'DELETE') => {
+        setRequestingId(modelId);
         try {
             const path = method === 'POST'
-                ? `/api/dictation/models/${LOCAL_TTS_MODEL_ID}/download`
-                : `/api/dictation/models/${LOCAL_TTS_MODEL_ID}`;
+                ? `/api/dictation/models/${modelId}/download`
+                : `/api/dictation/models/${modelId}`;
             await runtimeFetch(path, { method });
             await refresh();
         } catch {
             // Status refresh reports errors.
         } finally {
-            setRequesting(false);
+            setRequestingId(null);
         }
-    };
+    }, [refresh]);
 
-    if (!model) {
+    return { models, requestingId, request, refresh };
+};
+
+// Voices the picker offers: Kokoro speakers for the Kokoro models, one voice
+// per installed Piper model. Only installed models (plus the default) appear,
+// so a language model the server fetched on its own becomes selectable once
+// it is on disk.
+const buildLocalTtsVoiceOptions = (models: DictationModelState[]): LocalTtsVoiceOption[] => {
+    const options: LocalTtsVoiceOption[] = KOKORO_VOICE_OPTIONS.map((voice) => ({
+        modelId: LOCAL_TTS_MODEL_ID,
+        speakerId: voice.id,
+        label: voice.label,
+    }));
+    for (const model of models) {
+        if (model.id === LOCAL_TTS_MODEL_ID || !model.installed) continue;
+        if (model.id === KOKORO_MULTI_LANG_MODEL_ID) {
+            for (const voice of KOKORO_MULTI_LANG_VOICE_OPTIONS) {
+                options.push({ modelId: model.id, speakerId: voice.id, label: `${voice.label} · Kokoro zh/en` });
+            }
+            continue;
+        }
+        options.push({ modelId: model.id, speakerId: 0, label: model.description ?? model.id });
+    }
+    return options;
+};
+
+const LocalTtsModelStatus = ({ models, requestingId, request }: ReturnType<typeof useLocalTtsModels>) => {
+    const { t } = useI18n();
+
+    // The default English model is always listed; language models the server
+    // fetched on its own appear once they are installed or downloading, so
+    // the list shows what is on disk rather than the whole catalog.
+    const visible = models.filter((model) => model.id === LOCAL_TTS_MODEL_ID || model.installed || model.downloading);
+    if (visible.length === 0) {
         return null;
     }
 
     return (
-        <div className="flex items-center gap-2 py-1.5">
-            <span className="typography-ui-label text-foreground">Kokoro</span>
-            <span className="typography-ui-compact tabular-nums text-muted-foreground">305 MB</span>
-            {model.installed ? (
-                <>
-                    <Icon
-                        name="checkbox-circle"
-                        className="h-4 w-4 text-[var(--status-success)]"
-                        aria-label={t('settings.voice.page.stt.modelInstalled')}
-                    />
-                    <Button
-                        variant="ghost"
-                        size="xs"
-                        className="h-6 w-6 p-0 text-muted-foreground hover:text-[var(--status-error)]"
-                        disabled={requesting}
-                        onClick={() => { void request('DELETE'); }}
-                        title={t('settings.voice.page.stt.modelDelete')}
-                        aria-label={t('settings.voice.page.stt.modelDelete')}
-                    >
-                        <Icon name="delete-bin" className="h-4 w-4" />
-                    </Button>
-                </>
-            ) : model.downloading ? (
-                <span className="flex items-center gap-1.5">
-                    <Icon name="loader-4" className="h-3.5 w-3.5 animate-spin text-muted-foreground" />
-                    <span className="typography-ui-compact tabular-nums text-muted-foreground">
-                        {typeof model.downloadProgress === 'number' ? `${model.downloadProgress}%` : ''}
-                    </span>
-                </span>
-            ) : (
-                <Button
-                    variant="ghost"
-                    size="xs"
-                    className="h-6 w-6 p-0"
-                    disabled={requesting}
-                    onClick={() => { void request('POST'); }}
-                    title={t('settings.voice.page.stt.modelDownload')}
-                    aria-label={t('settings.voice.page.stt.modelDownload')}
-                >
-                    <Icon name="download" className="h-4 w-4" />
-                </Button>
-            )}
-            {model.downloadError ? (
-                <span className="typography-meta text-[var(--status-error)]">{model.downloadError}</span>
-            ) : null}
+        <div className="flex flex-col">
+            {visible.map((model) => (
+                <div key={model.id} className="flex items-center gap-2 py-1.5">
+                    <span className="typography-ui-label text-foreground">{model.description ?? model.id}</span>
+                    {model.installed ? (
+                        <>
+                            <Icon
+                                name="checkbox-circle"
+                                className="h-4 w-4 text-[var(--status-success)]"
+                                aria-label={t('settings.voice.page.stt.modelInstalled')}
+                            />
+                            <Button
+                                variant="ghost"
+                                size="xs"
+                                className="h-6 w-6 p-0 text-muted-foreground hover:text-[var(--status-error)]"
+                                disabled={requestingId !== null}
+                                onClick={() => { void request(model.id, 'DELETE'); }}
+                                title={t('settings.voice.page.stt.modelDelete')}
+                                aria-label={t('settings.voice.page.stt.modelDelete')}
+                            >
+                                <Icon name="delete-bin" className="h-4 w-4" />
+                            </Button>
+                        </>
+                    ) : model.downloading ? (
+                        <span className="flex items-center gap-1.5">
+                            <Icon name="loader-4" className="h-3.5 w-3.5 animate-spin text-muted-foreground" />
+                            <span className="typography-ui-compact tabular-nums text-muted-foreground">
+                                {typeof model.downloadProgress === 'number' ? `${model.downloadProgress}%` : ''}
+                            </span>
+                        </span>
+                    ) : (
+                        <Button
+                            variant="ghost"
+                            size="xs"
+                            className="h-6 w-6 p-0"
+                            disabled={requestingId !== null}
+                            onClick={() => { void request(model.id, 'POST'); }}
+                            title={t('settings.voice.page.stt.modelDownload')}
+                            aria-label={t('settings.voice.page.stt.modelDownload')}
+                        >
+                            <Icon name="download" className="h-4 w-4" />
+                        </Button>
+                    )}
+                    {model.downloadError ? (
+                        <span className="typography-meta text-[var(--status-error)]">{model.downloadError}</span>
+                    ) : null}
+                </div>
+            ))}
         </div>
     );
 };
@@ -424,6 +481,12 @@ export const VoiceSettings: React.FC = () => {
     const sayVoice = useConfigStore((state) => state.sayVoice);
     const setSayVoice = useConfigStore((state) => state.setSayVoice);
     const localTtsVoiceId = useConfigStore((state) => state.localTtsVoiceId);
+    const localTtsModelId = useConfigStore((state) => state.localTtsModelId);
+    const setLocalTtsModelId = useConfigStore((state) => state.setLocalTtsModelId);
+    const localTtsModels = useLocalTtsModels();
+    const localTtsVoiceOptions = useMemo(() => buildLocalTtsVoiceOptions(localTtsModels.models), [localTtsModels.models]);
+    const ttsFollowTextLanguage = useConfigStore((state) => state.ttsFollowTextLanguage);
+    const setTtsFollowTextLanguage = useConfigStore((state) => state.setTtsFollowTextLanguage);
     const setLocalTtsVoiceId = useConfigStore((state) => state.setLocalTtsVoiceId);
     const { speak: speakLocalTts, stop: stopLocalTts, isPlaying: isLocalTtsPlaying, error: localTtsError } = useLocalTTS();
 
@@ -432,13 +495,14 @@ export const VoiceSettings: React.FC = () => {
             stopLocalTts();
             return;
         }
-        const voiceLabel = KOKORO_VOICE_OPTIONS.find((v) => v.id === localTtsVoiceId)?.label
+        const voiceLabel = localTtsVoiceOptions.find((v) => v.modelId === localTtsModelId && v.speakerId === localTtsVoiceId)?.label
             ?? String(localTtsVoiceId);
         void speakLocalTts(t('settings.voice.page.preview.voiceLine', { voiceName: voiceLabel }), {
+            model: localTtsModelId,
             speakerId: localTtsVoiceId,
             speed: useConfigStore.getState().speechRate,
         });
-    }, [isLocalTtsPlaying, localTtsVoiceId, speakLocalTts, stopLocalTts, t]);
+    }, [isLocalTtsPlaying, localTtsModelId, localTtsVoiceId, localTtsVoiceOptions, speakLocalTts, stopLocalTts, t]);
     const browserVoice = useConfigStore((state) => state.browserVoice);
     const setBrowserVoice = useConfigStore((state) => state.setBrowserVoice);
     const openaiVoice = useConfigStore((state) => state.openaiVoice);
@@ -959,24 +1023,39 @@ export const VoiceSettings: React.FC = () => {
                             )}
 
                             {/* Local (Kokoro) TTS model status */}
-                            {voiceProvider === 'local' && <LocalTtsModelStatus />}
+                            {voiceProvider === 'local' && <LocalTtsModelStatus {...localTtsModels} />}
+
+                            {(voiceProvider === 'local' || voiceProvider === 'say') && (
+                                <SettingsCheckboxRow
+                                    checked={ttsFollowTextLanguage}
+                                    onChange={setTtsFollowTextLanguage}
+                                    label={t('settings.voice.page.field.followTextLanguage')}
+                                    ariaLabel={t('settings.voice.page.field.followTextLanguageAria')}
+                                    info={t('settings.voice.page.field.followTextLanguageInfo')}
+                                />
+                            )}
 
                             {/* Voice Selection */}
                             <SettingsFieldRow label={t('settings.voice.page.field.voice')}>
                                     {voiceProvider === 'local' && (
                                         <>
                                             <Select
-                                                value={String(localTtsVoiceId)}
-                                                onValueChange={(value) => setLocalTtsVoiceId(Number.parseInt(value, 10) || 0)}
+                                                value={localTtsVoiceKey(localTtsModelId, localTtsVoiceId)}
+                                                onValueChange={(value) => {
+                                                    const option = localTtsVoiceOptions.find((v) => localTtsVoiceKey(v.modelId, v.speakerId) === value);
+                                                    if (!option) return;
+                                                    setLocalTtsModelId(option.modelId);
+                                                    setLocalTtsVoiceId(option.speakerId);
+                                                }}
                                             >
                                                 <SelectTrigger size={SETTINGS_SELECT_SIZE} className={SETTINGS_SELECT_ROW_TRIGGER_CLASS}>
                                                     <SelectValue placeholder={t('settings.voice.page.field.selectVoicePlaceholder')}>
-                                                        {(value) => KOKORO_VOICE_OPTIONS.find((v) => String(v.id) === value)?.label ?? value}
+                                                        {(value) => localTtsVoiceOptions.find((v) => localTtsVoiceKey(v.modelId, v.speakerId) === value)?.label ?? value}
                                                     </SelectValue>
                                                 </SelectTrigger>
                                                 <SelectContent>
-                                                    {KOKORO_VOICE_OPTIONS.map((v) => (
-                                                        <SelectItem key={v.id} value={String(v.id)}>{v.label}</SelectItem>
+                                                    {localTtsVoiceOptions.map((v) => (
+                                                        <SelectItem key={localTtsVoiceKey(v.modelId, v.speakerId)} value={localTtsVoiceKey(v.modelId, v.speakerId)}>{v.label}</SelectItem>
                                                     ))}
                                                 </SelectContent>
                                             </Select>
diff --git a/packages/ui/src/hooks/useLocalTTS.ts b/packages/ui/src/hooks/useLocalTTS.ts
index 307356a2..0efc1a46 100644
--- a/packages/ui/src/hooks/useLocalTTS.ts
+++ b/packages/ui/src/hooks/useLocalTTS.ts
@@ -14,10 +14,18 @@ import { useCallback, useEffect, useRef, useState } from 'react';
 import { runtimeFetch } from '@/lib/runtime-fetch';
 
 export interface LocalTTSSpeakOptions {
-    /** Kokoro speaker id (0-10) */
+    /** Catalog id of the local model to use; defaults to the server's default model. */
+    model?: string;
+    /** Speaker id within the model (Kokoro voices; Piper models have one) */
     speakerId?: number;
     /** Playback speed multiplier (1.0 = normal) */
     speed?: number;
+    /**
+     * `'auto'`: the server picks a model and voice for the text's language.
+     * The language is judged on the whole message, not on each chunk sent for
+     * synthesis, so a short chunk cannot flip the voice mid-reply.
+     */
+    language?: 'auto';
     onStart?: () => void;
     onEnd?: () => void;
     onError?: (error: string) => void;
@@ -35,6 +43,8 @@ export interface UseLocalTTSReturn {
 /** Target chunk size: big enough to amortize requests, small enough for low latency. */
 const MIN_CHUNK_CHARS = 60;
 const MAX_CHUNK_CHARS = 400;
+// Enough of the message for language detection to see whole sentences.
+const LANGUAGE_SAMPLE_CHARS = 2000;
 
 /**
  * Split text into sentence-aligned chunks for pipelined synthesis.
@@ -170,6 +180,7 @@ export function useLocalTTS(): UseLocalTTSReturn {
 
         const session: PlaybackSession = { cancelled: false, abort: new AbortController() };
         sessionRef.current = session;
+        const languageSample = options?.language === 'auto' ? text.slice(0, LANGUAGE_SAMPLE_CHARS) : undefined;
 
         const fetchChunk = async (chunk: string): Promise<ArrayBuffer> => {
             const response = await runtimeFetch('/api/dictation/tts/speak', {
@@ -177,8 +188,11 @@ export function useLocalTTS(): UseLocalTTSReturn {
                 headers: { 'Content-Type': 'application/json' },
                 body: JSON.stringify({
                     text: chunk,
+                    model: options?.model,
                     ...(typeof options?.speakerId === 'number' ? { speakerId: options.speakerId } : {}),
                     ...(typeof options?.speed === 'number' ? { speed: options.speed } : {}),
+                    language: options?.language,
+                    languageSample,
                 }),
                 signal: session.abort.signal,
             });
diff --git a/packages/ui/src/hooks/useMessageTTS.ts b/packages/ui/src/hooks/useMessageTTS.ts
index 88e10615..4950e320 100644
--- a/packages/ui/src/hooks/useMessageTTS.ts
+++ b/packages/ui/src/hooks/useMessageTTS.ts
@@ -61,6 +61,8 @@ export function useMessageTTS(): UseMessageTTSReturn {
     const speechVolume = useConfigStore((state) => state.speechVolume);
     const sayVoice = useConfigStore((state) => state.sayVoice);
     const localTtsVoiceId = useConfigStore((state) => state.localTtsVoiceId);
+    const localTtsModelId = useConfigStore((state) => state.localTtsModelId);
+    const ttsFollowTextLanguage = useConfigStore((state) => state.ttsFollowTextLanguage);
     const browserVoice = useConfigStore((state) => state.browserVoice);
     const openaiVoice = useConfigStore((state) => state.openaiVoice);
     const openaiCompatibleVoice = useConfigStore((state) => state.openaiCompatibleVoice);
@@ -135,8 +137,10 @@ export function useMessageTTS(): UseMessageTTSReturn {
                 });
             } else if (voiceProvider === 'local') {
                 await speakLocalTTS(sanitizedText, {
+                    model: localTtsModelId,
                     speakerId: localTtsVoiceId,
                     speed: speechRate,
+                    language: ttsFollowTextLanguage ? 'auto' : undefined,
                     onEnd: () => setIsPlaying(false),
                     onError: () => setIsPlaying(false),
                 });
@@ -145,6 +149,7 @@ export function useMessageTTS(): UseMessageTTSReturn {
                 await speakSayTTS(sanitizedText, {
                     voice: sayVoice,
                     rate: wordsPerMinute,
+                    language: ttsFollowTextLanguage ? 'auto' : undefined,
                     onEnd: () => setIsPlaying(false),
                     onError: () => setIsPlaying(false),
                 });
@@ -187,6 +192,8 @@ export function useMessageTTS(): UseMessageTTSReturn {
         speakSayTTS,
         speakLocalTTS,
         localTtsVoiceId,
+        localTtsModelId,
+        ttsFollowTextLanguage,
         stop,
     ]);
     
diff --git a/packages/ui/src/hooks/useSayTTS.ts b/packages/ui/src/hooks/useSayTTS.ts
index c00353b1..f9108e6d 100644
--- a/packages/ui/src/hooks/useSayTTS.ts
+++ b/packages/ui/src/hooks/useSayTTS.ts
@@ -105,6 +105,8 @@ interface SpeakOptions {
   voice?: string;
   /** Speech rate in words per minute (defaults to 200) */
   rate?: number;
+  /** `'auto'`: the server switches to a voice that speaks the text's language. */
+  language?: 'auto';
   /** Callback when playback starts */
   onStart?: () => void;
   /** Callback when playback ends */
@@ -229,6 +231,7 @@ export function useSayTTS(options: UseSayTTSOptions = {}): UseSayTTSReturn {
           text: text.trim(),
           voice: options?.voice || 'Samantha',
           rate: options?.rate || 200,
+          language: options?.language,
         }),
         signal: abortControllerRef.current.signal,
       });
diff --git a/packages/ui/src/lib/i18n/messages/de.settings.ts b/packages/ui/src/lib/i18n/messages/de.settings.ts
index 75d596f9..86dc0985 100644
--- a/packages/ui/src/lib/i18n/messages/de.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/de.settings.ts
@@ -1795,7 +1795,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': 'Server',
   'settings.voice.page.provider.local': 'Lokal',
   'settings.voice.page.tooltip.sttLocal': 'On-device Transkription auf dem OpenChamber-Server. Modelle werden automatisch heruntergeladen; kein API-Schlüssel erforderlich.',
-  'settings.voice.page.tooltip.localTts': 'On-device Synthese auf dem OpenChamber-Server (Kokoro, Englisch). Das Modell wird automatisch heruntergeladen; kein API-Schlüssel erforderlich.',
+  'settings.voice.page.tooltip.localTts': 'On-Device-Synthese auf dem OpenChamber-Server (Kokoro für Englisch; Modelle für andere Sprachen werden beim ersten Einsatz geladen). Kein API-Schlüssel nötig.',
+  'settings.voice.page.field.followTextLanguage': 'Stimme an die Sprache des Textes anpassen',
+  'settings.voice.page.field.followTextLanguageAria': 'Stimme an die Sprache des Textes anpassen',
+  'settings.voice.page.field.followTextLanguageInfo': 'Ist eine Antwort in einer anderen Sprache, wird eine Stimme für diese Sprache verwendet: eine passende macOS-Stimme oder ein lokales Modell, das beim ersten Einsatz geladen wird.',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2 (Englisch)',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3 (25 europäische Sprachen)',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base (mehrsprachig)',
diff --git a/packages/ui/src/lib/i18n/messages/en.settings.ts b/packages/ui/src/lib/i18n/messages/en.settings.ts
index 95620f19..e0c6468f 100644
--- a/packages/ui/src/lib/i18n/messages/en.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/en.settings.ts
@@ -1862,7 +1862,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': 'Server',
   'settings.voice.page.provider.local': 'Local',
   'settings.voice.page.tooltip.sttLocal': 'On-device transcription on the OpenChamber server. Models download automatically; no API key needed.',
-  'settings.voice.page.tooltip.localTts': 'On-device synthesis on the OpenChamber server (Kokoro, English). The model downloads automatically; no API key needed.',
+  'settings.voice.page.tooltip.localTts': 'On-device synthesis on the OpenChamber server (Kokoro for English; models for other languages download on first use). No API key needed.',
+  'settings.voice.page.field.followTextLanguage': 'Match the voice to the language of the text',
+  'settings.voice.page.field.followTextLanguageAria': 'Match the voice to the language of the text',
+  'settings.voice.page.field.followTextLanguageInfo': 'When a reply is in another language, a voice for that language is used: a matching macOS voice, or a local model that downloads on first use.',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2 (English)',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3 (25 European languages)',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base (multilingual)',
diff --git a/packages/ui/src/lib/i18n/messages/es.settings.ts b/packages/ui/src/lib/i18n/messages/es.settings.ts
index fa40f214..b72f9e26 100644
--- a/packages/ui/src/lib/i18n/messages/es.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/es.settings.ts
@@ -1839,7 +1839,10 @@ export const settingsDict = {
   "settings.voice.page.provider.server": "Servidor",
   "settings.voice.page.provider.local": "Local",
   "settings.voice.page.tooltip.sttLocal": "Transcripción local en el servidor de OpenChamber. Los modelos se descargan automáticamente; no se necesita clave de API.",
-  "settings.voice.page.tooltip.localTts": "Síntesis local en el servidor de OpenChamber (Kokoro, inglés). El modelo se descarga automáticamente; no se necesita clave de API.",
+  "settings.voice.page.tooltip.localTts": "Síntesis local en el servidor de OpenChamber (Kokoro para inglés; los modelos de otros idiomas se descargan en el primer uso). No requiere clave de API.",
+  "settings.voice.page.field.followTextLanguage": "Ajustar la voz al idioma del texto",
+  "settings.voice.page.field.followTextLanguageAria": "Ajustar la voz al idioma del texto",
+  "settings.voice.page.field.followTextLanguageInfo": "Si una respuesta está en otro idioma, se usa una voz para ese idioma: una voz de macOS adecuada o un modelo local que se descarga en el primer uso.",
   "settings.voice.page.stt.model.parakeetV2": "Parakeet v2 (inglés)",
   "settings.voice.page.stt.model.parakeetV3": "Parakeet v3 (25 idiomas europeos)",
   "settings.voice.page.stt.model.whisperBase": "Whisper base (multilingüe)",
diff --git a/packages/ui/src/lib/i18n/messages/fr.settings.ts b/packages/ui/src/lib/i18n/messages/fr.settings.ts
index 432d536d..ae7d5d4e 100644
--- a/packages/ui/src/lib/i18n/messages/fr.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/fr.settings.ts
@@ -1757,7 +1757,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': 'Serveur',
   'settings.voice.page.provider.local': 'Local',
   'settings.voice.page.tooltip.sttLocal': 'Transcription locale sur le serveur OpenChamber. Les modèles se téléchargent automatiquement ; aucune clé d\'API requise.',
-  'settings.voice.page.tooltip.localTts': 'Synthèse locale sur le serveur OpenChamber (Kokoro, anglais). Le modèle se télécharge automatiquement ; aucune clé d’API requise.',
+  'settings.voice.page.tooltip.localTts': 'Synthèse locale sur le serveur OpenChamber (Kokoro pour l’anglais ; les modèles des autres langues sont téléchargés à la première utilisation). Aucune clé API requise.',
+  'settings.voice.page.field.followTextLanguage': 'Adapter la voix à la langue du texte',
+  'settings.voice.page.field.followTextLanguageAria': 'Adapter la voix à la langue du texte',
+  'settings.voice.page.field.followTextLanguageInfo': 'Si une réponse est dans une autre langue, une voix pour cette langue est utilisée : une voix macOS adaptée ou un modèle local téléchargé à la première utilisation.',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2 (anglais)',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3 (25 langues européennes)',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base (multilingue)',
diff --git a/packages/ui/src/lib/i18n/messages/ja.settings.ts b/packages/ui/src/lib/i18n/messages/ja.settings.ts
index 87b35b08..a68f0fc7 100644
--- a/packages/ui/src/lib/i18n/messages/ja.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/ja.settings.ts
@@ -1872,7 +1872,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': 'サーバー',
   'settings.voice.page.provider.local': 'ローカル',
   'settings.voice.page.tooltip.sttLocal': 'OpenChamber サーバー上でローカルに文字起こしします。モデルは自動でダウンロードされ、API キーは不要です。',
-  'settings.voice.page.tooltip.localTts': 'OpenChamber サーバー上でローカルに音声合成します（Kokoro、英語）。モデルは自動でダウンロードされ、API キーは不要です。',
+  'settings.voice.page.tooltip.localTts': 'OpenChamber サーバー上でローカルに音声合成します（英語は Kokoro、他の言語のモデルは初回使用時にダウンロード）。API キーは不要です。',
+  'settings.voice.page.field.followTextLanguage': 'テキストの言語に合わせて音声を選ぶ',
+  'settings.voice.page.field.followTextLanguageAria': 'テキストの言語に合わせて音声を選ぶ',
+  'settings.voice.page.field.followTextLanguageInfo': '返答が別の言語の場合、その言語の音声を使います。対応する macOS の音声、または初回使用時にダウンロードされるローカルモデルです。',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2（英語）',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3（ヨーロッパ25言語）',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base（多言語）',
diff --git a/packages/ui/src/lib/i18n/messages/ko.settings.ts b/packages/ui/src/lib/i18n/messages/ko.settings.ts
index 08ac89c7..4fdb93af 100644
--- a/packages/ui/src/lib/i18n/messages/ko.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/ko.settings.ts
@@ -1839,7 +1839,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': '서버',
   'settings.voice.page.provider.local': '로컬',
   'settings.voice.page.tooltip.sttLocal': 'OpenChamber 서버에서 로컬로 변환합니다. 모델은 자동으로 다운로드되며 API 키가 필요 없습니다.',
-  'settings.voice.page.tooltip.localTts': 'OpenChamber 서버에서 로컬로 음성을 합성합니다(Kokoro, 영어). 모델은 자동으로 다운로드되며 API 키가 필요 없습니다.',
+  'settings.voice.page.tooltip.localTts': 'OpenChamber 서버에서 로컬로 음성을 합성합니다(영어는 Kokoro, 다른 언어 모델은 처음 사용할 때 다운로드). API 키가 필요 없습니다.',
+  'settings.voice.page.field.followTextLanguage': '텍스트 언어에 맞는 음성 사용',
+  'settings.voice.page.field.followTextLanguageAria': '텍스트 언어에 맞는 음성 사용',
+  'settings.voice.page.field.followTextLanguageInfo': '응답이 다른 언어이면 해당 언어의 음성을 사용합니다. 일치하는 macOS 음성 또는 처음 사용할 때 다운로드되는 로컬 모델입니다.',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2 (영어)',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3 (유럽 25개 언어)',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base (다국어)',
diff --git a/packages/ui/src/lib/i18n/messages/pl.settings.ts b/packages/ui/src/lib/i18n/messages/pl.settings.ts
index ac8d5357..f8272cc1 100644
--- a/packages/ui/src/lib/i18n/messages/pl.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/pl.settings.ts
@@ -2176,7 +2176,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': 'Serwer',
   'settings.voice.page.provider.local': 'Lokalny',
   'settings.voice.page.tooltip.sttLocal': 'Transkrypcja lokalna na serwerze OpenChamber. Modele pobierają się automatycznie; klucz API nie jest potrzebny.',
-  'settings.voice.page.tooltip.localTts': 'Lokalna synteza na serwerze OpenChamber (Kokoro, angielski). Model pobiera się automatycznie; klucz API nie jest potrzebny.',
+  'settings.voice.page.tooltip.localTts': 'Lokalna synteza na serwerze OpenChamber (Kokoro dla angielskiego; modele innych języków pobierane przy pierwszym użyciu). Klucz API nie jest potrzebny.',
+  'settings.voice.page.field.followTextLanguage': 'Dopasuj głos do języka tekstu',
+  'settings.voice.page.field.followTextLanguageAria': 'Dopasuj głos do języka tekstu',
+  'settings.voice.page.field.followTextLanguageInfo': 'Gdy odpowiedź jest w innym języku, używany jest głos dla tego języka: pasujący głos macOS albo lokalny model pobierany przy pierwszym użyciu.',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2 (angielski)',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3 (25 języków europejskich)',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base (wielojęzyczny)',
diff --git a/packages/ui/src/lib/i18n/messages/pt-BR.settings.ts b/packages/ui/src/lib/i18n/messages/pt-BR.settings.ts
index fb5fa2c1..3f2827c5 100644
--- a/packages/ui/src/lib/i18n/messages/pt-BR.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/pt-BR.settings.ts
@@ -1839,7 +1839,10 @@ export const settingsDict = {
   "settings.voice.page.provider.server": "Servidor",
   "settings.voice.page.provider.local": "Local",
   "settings.voice.page.tooltip.sttLocal": "Transcrição local no servidor do OpenChamber. Os modelos são baixados automaticamente; não é necessária chave de API.",
-  "settings.voice.page.tooltip.localTts": "Síntese local no servidor do OpenChamber (Kokoro, inglês). O modelo é baixado automaticamente; não é necessária chave de API.",
+  "settings.voice.page.tooltip.localTts": "Síntese local no servidor do OpenChamber (Kokoro para inglês; modelos de outros idiomas são baixados no primeiro uso). Não requer chave de API.",
+  "settings.voice.page.field.followTextLanguage": "Ajustar a voz ao idioma do texto",
+  "settings.voice.page.field.followTextLanguageAria": "Ajustar a voz ao idioma do texto",
+  "settings.voice.page.field.followTextLanguageInfo": "Se uma resposta estiver em outro idioma, uma voz desse idioma é usada: uma voz do macOS correspondente ou um modelo local baixado no primeiro uso.",
   "settings.voice.page.stt.model.parakeetV2": "Parakeet v2 (inglês)",
   "settings.voice.page.stt.model.parakeetV3": "Parakeet v3 (25 idiomas europeus)",
   "settings.voice.page.stt.model.whisperBase": "Whisper base (multilíngue)",
diff --git a/packages/ui/src/lib/i18n/messages/tr.settings.ts b/packages/ui/src/lib/i18n/messages/tr.settings.ts
index c4ce2859..ead5621c 100644
--- a/packages/ui/src/lib/i18n/messages/tr.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/tr.settings.ts
@@ -1787,7 +1787,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': 'Sunucu',
   'settings.voice.page.provider.local': 'Yerel',
   'settings.voice.page.tooltip.sttLocal': 'OpenChamber sunucusunda cihaz üstü transkripsiyon. Modeller otomatik indirilir; API anahtarı gerekmez.',
-  'settings.voice.page.tooltip.localTts': 'OpenChamber sunucusunda cihaz üstü sentez (Kokoro, İngilizce). Model otomatik indirilir; API anahtarı gerekmez.',
+  'settings.voice.page.tooltip.localTts': 'OpenChamber sunucusunda yerel sentez (İngilizce için Kokoro; diğer dillerin modelleri ilk kullanımda indirilir). API anahtarı gerekmez.',
+  'settings.voice.page.field.followTextLanguage': 'Sesi metnin diline göre seç',
+  'settings.voice.page.field.followTextLanguageAria': 'Sesi metnin diline göre seç',
+  'settings.voice.page.field.followTextLanguageInfo': 'Yanıt başka bir dildeyse o dil için bir ses kullanılır: uygun bir macOS sesi veya ilk kullanımda indirilen yerel bir model.',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2 (İngilizce)',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3 (25 Avrupa dili)',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base (çok dilli)',
diff --git a/packages/ui/src/lib/i18n/messages/uk.settings.ts b/packages/ui/src/lib/i18n/messages/uk.settings.ts
index d65facf2..f3d88411 100644
--- a/packages/ui/src/lib/i18n/messages/uk.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/uk.settings.ts
@@ -1839,7 +1839,10 @@ export const settingsDict = {
   "settings.voice.page.provider.server": "Сервер",
   "settings.voice.page.provider.local": "Локальний",
   "settings.voice.page.tooltip.sttLocal": "Локальна розшифровка на сервері OpenChamber. Моделі завантажуються автоматично; ключ API не потрібен.",
-  "settings.voice.page.tooltip.localTts": "Локальний синтез на сервері OpenChamber (Kokoro, англійська). Модель завантажується автоматично; ключ API не потрібен.",
+  "settings.voice.page.tooltip.localTts": "Локальний синтез на сервері OpenChamber (Kokoro для англійської; моделі для інших мов завантажуються при першому використанні). Ключ API не потрібен.",
+  "settings.voice.page.field.followTextLanguage": "Підбирати голос під мову тексту",
+  "settings.voice.page.field.followTextLanguageAria": "Підбирати голос під мову тексту",
+  "settings.voice.page.field.followTextLanguageInfo": "Якщо відповідь іншою мовою, використовується голос цієї мови: відповідний голос macOS або локальна модель, яка завантажується при першому використанні.",
   "settings.voice.page.stt.model.parakeetV2": "Parakeet v2 (англійська)",
   "settings.voice.page.stt.model.parakeetV3": "Parakeet v3 (25 європейських мов)",
   "settings.voice.page.stt.model.whisperBase": "Whisper base (мультимовна)",
diff --git a/packages/ui/src/lib/i18n/messages/zh-CN.settings.ts b/packages/ui/src/lib/i18n/messages/zh-CN.settings.ts
index c7f1f622..c0eef58a 100644
--- a/packages/ui/src/lib/i18n/messages/zh-CN.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/zh-CN.settings.ts
@@ -1839,7 +1839,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': '服务器',
   'settings.voice.page.provider.local': '本地',
   'settings.voice.page.tooltip.sttLocal': '在 OpenChamber 服务器上本地转写。模型自动下载，无需 API 密钥。',
-  'settings.voice.page.tooltip.localTts': '在 OpenChamber 服务器上本地合成语音（Kokoro，英语）。模型自动下载，无需 API 密钥。',
+  'settings.voice.page.tooltip.localTts': '在 OpenChamber 服务器上本地合成语音（英语使用 Kokoro；其他语言的模型在首次使用时下载）。无需 API 密钥。',
+  'settings.voice.page.field.followTextLanguage': '根据文本语言匹配语音',
+  'settings.voice.page.field.followTextLanguageAria': '根据文本语言匹配语音',
+  'settings.voice.page.field.followTextLanguageInfo': '当回复使用其他语言时，将使用该语言的语音：匹配的 macOS 语音，或首次使用时下载的本地模型。',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2（英语）',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3（25 种欧洲语言）',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base（多语言）',
diff --git a/packages/ui/src/lib/i18n/messages/zh-TW.settings.ts b/packages/ui/src/lib/i18n/messages/zh-TW.settings.ts
index e24521ae..c0639769 100644
--- a/packages/ui/src/lib/i18n/messages/zh-TW.settings.ts
+++ b/packages/ui/src/lib/i18n/messages/zh-TW.settings.ts
@@ -1746,7 +1746,10 @@ export const settingsDict = {
   'settings.voice.page.provider.server': '伺服器',
   'settings.voice.page.provider.local': '本機',
   'settings.voice.page.tooltip.sttLocal': '在 OpenChamber 伺服器上本機轉寫。模型會自動下載，無需 API 金鑰。',
-  'settings.voice.page.tooltip.localTts': '在 OpenChamber 伺服器上本機合成語音（Kokoro，英文）。模型會自動下載，無需 API 金鑰。',
+  'settings.voice.page.tooltip.localTts': '在 OpenChamber 伺服器上本機合成語音（英文使用 Kokoro；其他語言的模型在首次使用時下載）。不需要 API 金鑰。',
+  'settings.voice.page.field.followTextLanguage': '依文字語言選擇語音',
+  'settings.voice.page.field.followTextLanguageAria': '依文字語言選擇語音',
+  'settings.voice.page.field.followTextLanguageInfo': '當回覆使用其他語言時，會使用該語言的語音：相符的 macOS 語音，或首次使用時下載的本機模型。',
   'settings.voice.page.stt.model.parakeetV2': 'Parakeet v2（英文）',
   'settings.voice.page.stt.model.parakeetV3': 'Parakeet v3（25 種歐洲語言）',
   'settings.voice.page.stt.model.whisperBase': 'Whisper base（多語言）',
diff --git a/packages/ui/src/stores/useConfigStore.ts b/packages/ui/src/stores/useConfigStore.ts
index b4a370ca..66f1487e 100644
--- a/packages/ui/src/stores/useConfigStore.ts
+++ b/packages/ui/src/stores/useConfigStore.ts
@@ -1067,6 +1067,10 @@ interface ConfigStore {
     sayVoice: string;
     browserVoice: string;
     localTtsVoiceId: number;
+    /** Local TTS model the chosen voice belongs to (catalog id). */
+    localTtsModelId: string;
+    /** Local and macOS voices follow the language of the text being read. */
+    ttsFollowTextLanguage: boolean;
     openaiVoice: string;
     openaiApiKey: string;
     openaiCompatibleUrl: string;
@@ -1094,6 +1098,8 @@ interface ConfigStore {
     setSayVoice: (voice: string) => void;
     setBrowserVoice: (voice: string) => void;
     setLocalTtsVoiceId: (voiceId: number) => void;
+    setLocalTtsModelId: (modelId: string) => void;
+    setTtsFollowTextLanguage: (enabled: boolean) => void;
     setOpenaiVoice: (voice: string) => void;
     setOpenaiApiKey: (apiKey: string) => void;
     setOpenaiCompatibleUrl: (url: string) => void;
@@ -1277,6 +1283,21 @@ export const useConfigStore = create<ConfigStore>()(
                     }
                     return 0;
                 })(),
+                localTtsModelId: (() => {
+                    if (typeof window !== 'undefined') {
+                        const saved = localStorage.getItem('localTtsModelId');
+                        if (saved) return saved;
+                    }
+                    return 'kokoro-en-v0_19';
+                })(),
+
+                ttsFollowTextLanguage: (() => {
+                    if (typeof window !== 'undefined') {
+                        const saved = localStorage.getItem('ttsFollowTextLanguage');
+                        if (saved !== null) return saved === 'true';
+                    }
+                    return true;
+                })(),
                 // Browser voice - load from localStorage or default to empty (auto-select)
                 browserVoice: (() => {
                     if (typeof window !== 'undefined') {
@@ -2962,6 +2983,20 @@ export const useConfigStore = create<ConfigStore>()(
                     }
                 },
 
+                setLocalTtsModelId: (modelId: string) => {
+                    set({ localTtsModelId: modelId });
+                    if (typeof window !== 'undefined') {
+                        localStorage.setItem('localTtsModelId', modelId);
+                    }
+                },
+
+                setTtsFollowTextLanguage: (enabled: boolean) => {
+                    set({ ttsFollowTextLanguage: enabled });
+                    if (typeof window !== 'undefined') {
+                        localStorage.setItem('ttsFollowTextLanguage', String(enabled));
+                    }
+                },
+
                 setBrowserVoice: (voice: string) => {
                     set({ browserVoice: voice });
                     if (typeof window !== 'undefined') {
diff --git a/packages/web/server/lib/dictation/DOCUMENTATION.md b/packages/web/server/lib/dictation/DOCUMENTATION.md
index e66af116..49e38aae 100644
--- a/packages/web/server/lib/dictation/DOCUMENTATION.md
+++ b/packages/web/server/lib/dictation/DOCUMENTATION.md
@@ -11,12 +11,25 @@ live transcript costs O(n^2) work for a result the final decode replaces. The
 composer shows no text while recording and inserts the full transcript on
 stop.
 
-Local TTS (Kokoro via sherpa-onnx OfflineTts) runs in the same worker process
-and is exposed as `POST /api/dictation/tts/speak` (JSON `{text, speakerId?,
-speed?, model?}` → WAV bytes; 503 with `reasonCode` while the model is
-downloading). TTS models live in the same catalog/downloader as STT models
-(`local/model-catalog.js` `LOCAL_TTS_MODEL_CATALOG`) and are managed by the
-same status/download/delete routes.
+Local TTS (Kokoro and Piper/VITS via sherpa-onnx OfflineTts) runs in the same
+worker process and is exposed as `POST /api/dictation/tts/speak` (JSON
+`{text, speakerId?, speed?, model?, language?, languageSample?}` → WAV bytes; 503 with
+`reasonCode` while the model is downloading). TTS models live in the same
+catalog/downloader as STT models (`local/model-catalog.js`
+`LOCAL_TTS_MODEL_CATALOG`) and are managed by the same status/download/delete
+routes.
+
+Each TTS catalog entry declares the `languages` it speaks. With
+`language: 'auto'` the service detects the language of `languageSample` — the
+whole message the chunk belongs to, sent by the client with every chunk — or
+of `text` when no sample is given
+(`../tts/language-detect.js`, script plus function-word scoring, no
+dependencies) and keeps the caller's model when it speaks that language;
+otherwise it switches to the catalog model for the language, downloading it on
+first use like any other model, and starts from that model's default speaker
+(`defaultSpeakerByLanguage`) instead of the caller's speaker id. A language no
+catalog model covers keeps the caller's model, so text is always spoken. The
+response carries `X-Speech-Model` and `X-Speech-Language`.
 
 ## Ownership
 
diff --git a/packages/web/server/lib/dictation/local/model-catalog.js b/packages/web/server/lib/dictation/local/model-catalog.js
index 29ea524b..16af62c9 100644
--- a/packages/web/server/lib/dictation/local/model-catalog.js
+++ b/packages/web/server/lib/dictation/local/model-catalog.js
@@ -68,9 +68,19 @@ export const LOCAL_STT_MODEL_CATALOG = {
  * Local text-to-speech models (sherpa-onnx OfflineTts). Downloaded and
  * managed through the same pipeline as the STT models.
  */
+/**
+ * Local text-to-speech models (sherpa-onnx OfflineTts). Downloaded and
+ * managed through the same pipeline as the STT models.
+ *
+ * `languages` lists the languages a model speaks well; the speech service
+ * uses it to pick a model for the language a text is written in. Kokoro
+ * models carry speaker ids (`voices`); a Piper model is one voice for one
+ * language. `lexicon` entries are joined with commas for sherpa-onnx.
+ */
 export const LOCAL_TTS_MODEL_CATALOG = {
   'kokoro-en-v0_19': {
     type: 'kokoro',
+    languages: ['en'],
     archiveUrl:
       'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/kokoro-en-v0_19.tar.bz2',
     extractedDir: 'kokoro-en-v0_19',
@@ -82,6 +92,188 @@ export const LOCAL_TTS_MODEL_CATALOG = {
     },
     description: 'Kokoro TTS (English, natural voices)',
   },
+  'kokoro-multi-lang-v1_1': {
+    type: 'kokoro',
+    languages: ['zh', 'en'],
+    // sherpa-onnx wires this Kokoro build for Chinese and English only;
+    // speakers 0-2 are English, 3-102 Chinese.
+    defaultSpeakerByLanguage: { en: 0, zh: 3 },
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/kokoro-multi-lang-v1_1.tar.bz2',
+    extractedDir: 'kokoro-multi-lang-v1_1',
+    files: {
+      model: 'model.onnx',
+      voices: 'voices.bin',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+      lexiconEnglish: 'lexicon-us-en.txt',
+      lexiconChinese: 'lexicon-zh.txt',
+    },
+    lexicon: ['lexiconEnglish', 'lexiconChinese'],
+    description: 'Kokoro TTS (Chinese and English, 103 voices)',
+  },
+  // The larger `ukrainian_tts-medium` build is a character-level model
+  // (`phoneme_type: text`); sherpa-onnx phonemizes every Piper model through
+  // espeak-ng, which turns that one into noise. `vits-coqui-uk-mai` sounds
+  // better but reads Cyrillic only and drops every Latin word (file names,
+  // product names), which is unusable in a coding chat. Lada is an espeak
+  // model: small, but it reads mixed text.
+  'piper-uk_UA-lada-x_low': {
+    type: 'vits',
+    languages: ['uk'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-uk_UA-lada-x_low.tar.bz2',
+    extractedDir: 'vits-piper-uk_UA-lada-x_low',
+    files: {
+      model: 'uk_UA-lada-x_low.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Ukrainian)',
+  },
+  'piper-de_DE-thorsten-medium': {
+    type: 'vits',
+    languages: ['de'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-de_DE-thorsten-medium.tar.bz2',
+    extractedDir: 'vits-piper-de_DE-thorsten-medium',
+    files: {
+      model: 'de_DE-thorsten-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (German)',
+  },
+  'piper-fr_FR-siwis-medium': {
+    type: 'vits',
+    languages: ['fr'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-fr_FR-siwis-medium.tar.bz2',
+    extractedDir: 'vits-piper-fr_FR-siwis-medium',
+    files: {
+      model: 'fr_FR-siwis-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (French)',
+  },
+  'piper-es_ES-davefx-medium': {
+    type: 'vits',
+    languages: ['es'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-es_ES-davefx-medium.tar.bz2',
+    extractedDir: 'vits-piper-es_ES-davefx-medium',
+    files: {
+      model: 'es_ES-davefx-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Spanish)',
+  },
+  'piper-it_IT-paola-medium': {
+    type: 'vits',
+    languages: ['it'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-it_IT-paola-medium.tar.bz2',
+    extractedDir: 'vits-piper-it_IT-paola-medium',
+    files: {
+      model: 'it_IT-paola-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Italian)',
+  },
+  'piper-pt_BR-faber-medium': {
+    type: 'vits',
+    languages: ['pt'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-pt_BR-faber-medium.tar.bz2',
+    extractedDir: 'vits-piper-pt_BR-faber-medium',
+    files: {
+      model: 'pt_BR-faber-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Portuguese (Brazil))',
+  },
+  'piper-pl_PL-gosia-medium': {
+    type: 'vits',
+    languages: ['pl'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-pl_PL-gosia-medium.tar.bz2',
+    extractedDir: 'vits-piper-pl_PL-gosia-medium',
+    files: {
+      model: 'pl_PL-gosia-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Polish)',
+  },
+  'piper-ru_RU-irina-medium': {
+    type: 'vits',
+    languages: ['ru'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-ru_RU-irina-medium.tar.bz2',
+    extractedDir: 'vits-piper-ru_RU-irina-medium',
+    files: {
+      model: 'ru_RU-irina-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Russian)',
+  },
+  'piper-nl_NL-pim-medium': {
+    type: 'vits',
+    languages: ['nl'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-nl_NL-pim-medium.tar.bz2',
+    extractedDir: 'vits-piper-nl_NL-pim-medium',
+    files: {
+      model: 'nl_NL-pim-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Dutch)',
+  },
+  'piper-cs_CZ-jirka-medium': {
+    type: 'vits',
+    languages: ['cs'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-cs_CZ-jirka-medium.tar.bz2',
+    extractedDir: 'vits-piper-cs_CZ-jirka-medium',
+    files: {
+      model: 'cs_CZ-jirka-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Czech)',
+  },
+  'piper-tr_TR-dfki-medium': {
+    type: 'vits',
+    languages: ['tr'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-tr_TR-dfki-medium.tar.bz2',
+    extractedDir: 'vits-piper-tr_TR-dfki-medium',
+    files: {
+      model: 'tr_TR-dfki-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Turkish)',
+  },
+  'piper-sv_SE-nst-medium': {
+    type: 'vits',
+    languages: ['sv'],
+    archiveUrl:
+      'https://github.com/k2-fsa/sherpa-onnx/releases/download/tts-models/vits-piper-sv_SE-nst-medium.tar.bz2',
+    extractedDir: 'vits-piper-sv_SE-nst-medium',
+    files: {
+      model: 'sv_SE-nst-medium.onnx',
+      tokens: 'tokens.txt',
+      espeakData: 'espeak-ng-data',
+    },
+    description: 'Piper TTS (Swedish)',
+  },
 };
 
 export const DEFAULT_LOCAL_STT_MODEL = 'parakeet-tdt-0.6b-v2-int8';
@@ -131,6 +323,34 @@ export function getLocalSttModelSpec(modelId) {
   };
 }
 
+/**
+ * The local TTS model to use for a language, preferring the model the user
+ * selected when it speaks that language. Returns null when no catalog model
+ * covers the language, in which case callers keep the selected model.
+ * @param {string} language BCP-47 primary subtag (`uk`, `zh`...)
+ * @param {string} [preferredModelId]
+ * @returns {string | null}
+ */
+export function resolveLocalTtsModelForLanguage(language, preferredModelId) {
+  const speaks = (modelId) => LOCAL_TTS_MODEL_CATALOG[modelId]?.languages?.includes(language) === true;
+  if (preferredModelId && speaks(preferredModelId)) return preferredModelId;
+  const candidate = LOCAL_TTS_MODEL_IDS.find(speaks);
+  return candidate ?? null;
+}
+
+/**
+ * The speaker id a model should use for a language when the caller's
+ * speaker was chosen for another language. `undefined` keeps the caller's
+ * speaker.
+ * @param {string} modelId
+ * @param {string} language
+ * @returns {number | undefined}
+ */
+export function getLocalTtsDefaultSpeaker(modelId, language) {
+  const speaker = LOCAL_TTS_MODEL_CATALOG[modelId]?.defaultSpeakerByLanguage?.[language];
+  return Number.isInteger(speaker) ? speaker : undefined;
+}
+
 /**
  * @param {string} modelsDir
  * @param {string} modelId
diff --git a/packages/web/server/lib/dictation/local/model-catalog.test.js b/packages/web/server/lib/dictation/local/model-catalog.test.js
new file mode 100644
index 00000000..e14a66aa
--- /dev/null
+++ b/packages/web/server/lib/dictation/local/model-catalog.test.js
@@ -0,0 +1,42 @@
+import { describe, expect, it } from 'vitest';
+import {
+  DEFAULT_LOCAL_TTS_MODEL,
+  LOCAL_TTS_MODEL_CATALOG,
+  getLocalSttModelSpec,
+  getLocalTtsDefaultSpeaker,
+  resolveLocalTtsModelForLanguage,
+} from './model-catalog.js';
+
+describe('local TTS catalog', () => {
+  it('keeps the selected model when it speaks the language', () => {
+    expect(resolveLocalTtsModelForLanguage('en', DEFAULT_LOCAL_TTS_MODEL)).toBe(DEFAULT_LOCAL_TTS_MODEL);
+    expect(resolveLocalTtsModelForLanguage('zh', 'kokoro-multi-lang-v1_1')).toBe('kokoro-multi-lang-v1_1');
+  });
+
+  it('picks a catalog model for a language the selected model lacks', () => {
+    expect(resolveLocalTtsModelForLanguage('uk', DEFAULT_LOCAL_TTS_MODEL)).toBe('piper-uk_UA-lada-x_low');
+    expect(resolveLocalTtsModelForLanguage('zh', DEFAULT_LOCAL_TTS_MODEL)).toBe('kokoro-multi-lang-v1_1');
+  });
+
+  it('returns null for a language no model covers', () => {
+    expect(resolveLocalTtsModelForLanguage('xx', DEFAULT_LOCAL_TTS_MODEL)).toBeNull();
+  });
+
+  it('gives Chinese a Chinese speaker on the multi-language Kokoro', () => {
+    expect(getLocalTtsDefaultSpeaker('kokoro-multi-lang-v1_1', 'zh')).toBe(3);
+    expect(getLocalTtsDefaultSpeaker('kokoro-multi-lang-v1_1', 'en')).toBe(0);
+    expect(getLocalTtsDefaultSpeaker('piper-uk_UA-lada-x_low', 'uk')).toBeUndefined();
+  });
+
+  it('every TTS entry declares its languages and installable files', () => {
+    for (const [id, spec] of Object.entries(LOCAL_TTS_MODEL_CATALOG)) {
+      expect(spec.languages.length, id).toBeGreaterThan(0);
+      expect(spec.archiveUrl, id).toMatch(/^https:\/\/github\.com\/k2-fsa\/sherpa-onnx\/releases\/download\/tts-models\//);
+      const resolved = getLocalSttModelSpec(id);
+      expect(resolved.requiredFiles, id).toContain(spec.files.model);
+      for (const key of spec.lexicon ?? []) {
+        expect(spec.files[key], `${id} lexicon ${key}`).toBeTruthy();
+      }
+    }
+  });
+});
diff --git a/packages/web/server/lib/dictation/local/sherpa-tts.js b/packages/web/server/lib/dictation/local/sherpa-tts.js
index f4fa7972..589bae69 100644
--- a/packages/web/server/lib/dictation/local/sherpa-tts.js
+++ b/packages/web/server/lib/dictation/local/sherpa-tts.js
@@ -1,5 +1,5 @@
 /**
- * Sherpa-onnx offline TTS (Kokoro). Runs inside the dictation worker process
+ * Sherpa-onnx offline TTS (Kokoro and Piper/VITS). Runs inside the dictation worker process
  * only — never load the native addon in the main server process.
  */
 
@@ -23,20 +23,49 @@ function float32ToPcm16le(samples) {
   return Buffer.from(out.buffer, out.byteOffset, out.byteLength);
 }
 
+/**
+ * sherpa-onnx model config for one catalog entry. Kokoro carries a voices
+ * bank (speaker ids) and optional lexicons; a Piper/VITS model is a single
+ * voice with espeak-ng phonemization.
+ * @param {{ modelDir: string, type?: string, files: Record<string, string>, lexicon?: string[] }} config
+ */
+function buildModelConfig(config) {
+  const file = (key, label) => {
+    const filePath = path.join(config.modelDir, config.files[key]);
+    assertFileExists(filePath, label);
+    return filePath;
+  };
+  const modelPath = file('model', 'TTS model');
+  const tokensPath = file('tokens', 'TTS tokens');
+
+  if (config.type === 'vits') {
+    // Piper models phonemize through espeak-ng (`espeakData`); character
+    // models (Coqui) read the text directly and carry no espeak data.
+    const dataDir = config.files.espeakData ? file('espeakData', 'TTS espeak-ng dataDir') : '';
+    return { vits: { model: modelPath, tokens: tokensPath, ...(dataDir ? { dataDir } : {}), lengthScale: 1.0 } };
+  }
+
+  const dataDir = file('espeakData', 'TTS espeak-ng dataDir');
+  const voicesPath = file('voices', 'TTS voices');
+  const lexicon = (config.lexicon ?? []).map((key) => file(key, 'TTS lexicon')).join(',');
+  return {
+    kokoro: {
+      model: modelPath,
+      voices: voicesPath,
+      tokens: tokensPath,
+      dataDir,
+      lengthScale: 1.0,
+      ...(lexicon ? { lexicon } : {}),
+    },
+  };
+}
+
 export class SherpaTtsEngine {
   /**
-   * @param {{ modelDir: string, files: { model: string, voices: string, tokens: string, espeakData: string }, numThreads?: number }} config
+   * @param {{ modelDir: string, type?: string, files: Record<string, string>, lexicon?: string[], numThreads?: number }} config
    */
   constructor(config) {
-    const modelPath = path.join(config.modelDir, config.files.model);
-    const voicesPath = path.join(config.modelDir, config.files.voices);
-    const tokensPath = path.join(config.modelDir, config.files.tokens);
-    const dataDir = path.join(config.modelDir, config.files.espeakData);
-
-    assertFileExists(modelPath, 'TTS model');
-    assertFileExists(voicesPath, 'TTS voices');
-    assertFileExists(tokensPath, 'TTS tokens');
-    assertFileExists(dataDir, 'TTS espeak-ng dataDir');
+    const model = buildModelConfig(config);
 
     const sherpa = loadSherpaOnnxNode();
     if (typeof sherpa.OfflineTts !== 'function') {
@@ -44,15 +73,7 @@ export class SherpaTtsEngine {
     }
 
     this.tts = new sherpa.OfflineTts({
-      model: {
-        kokoro: {
-          model: modelPath,
-          voices: voicesPath,
-          tokens: tokensPath,
-          dataDir,
-          lengthScale: 1.0,
-        },
-      },
+      model,
       numThreads: config.numThreads ?? 2,
       provider: 'cpu',
       maxNumSentences: 1,
diff --git a/packages/web/server/lib/dictation/local/worker-process.js b/packages/web/server/lib/dictation/local/worker-process.js
index 3a5c34b8..06a7ac8b 100644
--- a/packages/web/server/lib/dictation/local/worker-process.js
+++ b/packages/web/server/lib/dictation/local/worker-process.js
@@ -102,7 +102,9 @@ function getTtsEngine(modelsDir, modelId) {
   const spec = getLocalSttModelSpec(modelId);
   const created = new SherpaTtsEngine({
     modelDir: getLocalSttModelDir(modelsDir, modelId),
+    type: spec.type,
     files: spec.files,
+    lexicon: spec.lexicon,
     numThreads: 2,
   });
   ttsEngines.set(key, created);
diff --git a/packages/web/server/lib/dictation/runtime.js b/packages/web/server/lib/dictation/runtime.js
index 8fae1fcf..59437a12 100644
--- a/packages/web/server/lib/dictation/runtime.js
+++ b/packages/web/server/lib/dictation/runtime.js
@@ -63,6 +63,8 @@ export function createDictationRuntime({
         model: typeof req.body?.model === 'string' ? req.body.model : undefined,
         speakerId: Number.isInteger(req.body?.speakerId) ? req.body.speakerId : undefined,
         speed: typeof req.body?.speed === 'number' ? req.body.speed : undefined,
+        language: req.body?.language === 'auto' ? 'auto' : undefined,
+        languageSample: typeof req.body?.languageSample === 'string' ? req.body.languageSample.slice(0, 4000) : undefined,
       });
       if (result.error) {
         res.status(503).json({
@@ -73,6 +75,8 @@ export function createDictationRuntime({
         return;
       }
       res.setHeader('Content-Type', result.format || 'audio/wav');
+      res.setHeader('X-Speech-Model', result.modelId);
+      if (result.language) res.setHeader('X-Speech-Language', result.language);
       res.send(result.audio);
     } catch (error) {
       res.status(500).json({ error: error?.message || 'Failed to synthesize speech' });
diff --git a/packages/web/server/lib/dictation/service.js b/packages/web/server/lib/dictation/service.js
index 7dc555d2..e40bc253 100644
--- a/packages/web/server/lib/dictation/service.js
+++ b/packages/web/server/lib/dictation/service.js
@@ -1,3 +1,4 @@
+import { detectTextLanguage } from '../tts/language-detect.js';
 /**
  * Dictation service: resolves STT providers, tracks local model download
  * state, and exposes a readiness snapshot for the status route.
@@ -16,6 +17,8 @@ import { OpenAICompatibleTranscriptionSession } from './openai-compatible-sessio
 import {
   DEFAULT_LOCAL_STT_MODEL,
   DEFAULT_LOCAL_TTS_MODEL,
+  getLocalTtsDefaultSpeaker,
+  resolveLocalTtsModelForLanguage,
   LOCAL_STT_MODEL_CATALOG,
   LOCAL_STT_MODEL_IDS,
   LOCAL_TTS_MODEL_CATALOG,
@@ -220,10 +223,30 @@ export function createDictationService({ modelsDir }) {
   /**
    * Synthesize speech with the local TTS model. Returns WAV bytes, or a
    * readiness error while the model is missing/downloading.
-   * @param {{ text: string, model?: string, speakerId?: number, speed?: number }} options
+   *
+   * With `language: 'auto'` the text's language decides the model: the
+   * caller's model when it speaks that language, otherwise the catalog
+   * model for it (downloaded on first use, reported as in-progress until it
+   * lands). The caller's speaker id is kept only on the caller's model; a
+   * substitute model starts from its own default speaker for the language.
+   * A language no catalog model covers keeps the caller's model, so text is
+   * never silently dropped.
+   * `languageSample` is the whole message the chunk belongs to (or a prefix
+   * of it): the language is judged on that, never on a short chunk alone.
+   * @param {{ text: string, model?: string, speakerId?: number, speed?: number, language?: string, languageSample?: string }} options
    */
-  const synthesizeSpeech = async ({ text, model, speakerId, speed }) => {
-    const modelId = isLocalTtsModelId(model) ? model : DEFAULT_LOCAL_TTS_MODEL;
+  const synthesizeSpeech = async ({ text, model, speakerId, speed, language, languageSample }) => {
+    const requestedModelId = isLocalTtsModelId(model) ? model : DEFAULT_LOCAL_TTS_MODEL;
+    let modelId = requestedModelId;
+    let resolvedLanguage = null;
+    if (language === 'auto') {
+      resolvedLanguage = detectTextLanguage(languageSample || text).language;
+      const forLanguage = resolveLocalTtsModelForLanguage(resolvedLanguage, requestedModelId);
+      if (forLanguage && forLanguage !== requestedModelId) {
+        modelId = forLanguage;
+        speakerId = getLocalTtsDefaultSpeaker(modelId, resolvedLanguage);
+      }
+    }
     const installed = await isLocalSttModelInstalled(modelsDir, modelId);
     if (!installed) {
       const state = downloadStates.get(modelId);
@@ -251,7 +274,7 @@ export function createDictationService({ modelsDir }) {
       speakerId,
       speed,
     });
-    return { audio: result.audio, format: result.format };
+    return { audio: result.audio, format: result.format, modelId, language: resolvedLanguage };
   };
 
   /**
diff --git a/packages/web/server/lib/tts/DOCUMENTATION.md b/packages/web/server/lib/tts/DOCUMENTATION.md
index 81a46760..2e0c4352 100644
--- a/packages/web/server/lib/tts/DOCUMENTATION.md
+++ b/packages/web/server/lib/tts/DOCUMENTATION.md
@@ -11,6 +11,7 @@ This module provides server-side Text-to-Speech services using OpenAI's TTS API.
 - `packages/web/server/lib/text/summarization.js`: Shared text summarization stub and sanitization utilities. It performs no external Zen calls.
 - `packages/web/server/lib/tts/stt.js`: STT proxy for OpenAI-compatible transcription endpoints.
 - `packages/web/server/lib/tts/base-url.js`: shared base URL validation and normalization for custom OpenAI-compatible endpoints.
+- `packages/web/server/lib/tts/language-detect.js`: dependency-free language detection for voice selection (`detectTextLanguage`, `pickVoiceForLanguage`, `languageOfLocale`). Used by the macOS `say` route (`language: 'auto'` switches to an installed voice whose locale matches the text; the response carries `X-Speech-Voice` and `X-Speech-Language`) and by the dictation module's local TTS model choice.
 
 ## Public exports
 
diff --git a/packages/web/server/lib/tts/language-detect.js b/packages/web/server/lib/tts/language-detect.js
new file mode 100644
index 00000000..d87968e6
--- /dev/null
+++ b/packages/web/server/lib/tts/language-detect.js
@@ -0,0 +1,210 @@
+/**
+ * Language detection for text-to-speech voice selection.
+ *
+ * Picks the language a piece of chat text is written in so a TTS provider
+ * can choose a matching voice or model. Deliberately small and dependency
+ * free: the writing system decides most cases outright, and Latin-script
+ * languages are told apart by function words and characteristic letters.
+ * The answer is a best effort for voice selection, not a linguistic claim —
+ * an unknown language falls back to English rather than failing.
+ */
+
+const SCRIPT_RANGES = [
+  ['hangul', /[가-힯ᄀ-ᇿ㄰-㆏]/g],
+  ['kana', /[぀-ヿ]/g],
+  ['han', /[一-鿿㐀-䶿]/g],
+  ['cyrillic', /[Ѐ-ӿ]/g],
+  ['greek', /[Ͱ-Ͽ]/g],
+  ['arabic', /[؀-ۿ]/g],
+  ['hebrew', /[֐-׿]/g],
+  ['thai', /[฀-๿]/g],
+  ['devanagari', /[ऀ-ॿ]/g],
+  ['latin', /[A-Za-zÀ-ɏ]/g],
+];
+
+const SCRIPT_LANGUAGE = {
+  hangul: 'ko',
+  greek: 'el',
+  arabic: 'ar',
+  hebrew: 'he',
+  thai: 'th',
+  devanagari: 'hi',
+};
+
+// Letters that only (or overwhelmingly) occur in one language of a script.
+const LATIN_MARKERS = {
+  pl: /[łęąńśźż]/i,
+  cs: /[řěůťďň]/i,
+  tr: /[ğışİ]/,
+  pt: /[ãõ]/i,
+  es: /[ñ¿¡]/,
+  de: /[ß]/,
+  fr: /[œ]/i,
+  sv: /[å]/i,
+};
+
+// Frequent function words per language. Scored by whole-word hits; every
+// list has the same length so scores stay comparable.
+const STOPWORDS = {
+  en: ['the', 'and', 'is', 'to', 'of', 'that', 'you', 'with', 'for', 'this', 'are', 'it', 'not', 'have', 'can', 'will', 'your', 'from', 'which', 'when'],
+  de: ['und', 'der', 'die', 'das', 'ist', 'nicht', 'mit', 'ein', 'eine', 'auch', 'sich', 'auf', 'für', 'wird', 'werden', 'oder', 'aber', 'wenn', 'sind', 'kann'],
+  fr: ['le', 'la', 'les', 'et', 'est', 'une', 'des', 'pour', 'que', 'qui', 'dans', 'pas', 'vous', 'sur', 'avec', 'sont', 'nous', 'cette', 'mais', 'plus'],
+  es: ['el', 'la', 'los', 'las', 'que', 'es', 'una', 'por', 'para', 'con', 'del', 'como', 'pero', 'más', 'este', 'esta', 'son', 'tiene', 'puede', 'también'],
+  it: ['il', 'la', 'che', 'di', 'è', 'una', 'per', 'non', 'con', 'del', 'della', 'come', 'sono', 'anche', 'questo', 'questa', 'gli', 'nel', 'più', 'essere'],
+  pt: ['o', 'a', 'os', 'as', 'que', 'é', 'uma', 'para', 'com', 'não', 'do', 'da', 'como', 'mas', 'também', 'este', 'esta', 'são', 'você', 'pode'],
+  pl: ['i', 'nie', 'jest', 'się', 'na', 'to', 'że', 'jak', 'ale', 'dla', 'oraz', 'przez', 'czy', 'tym', 'jego', 'można', 'jeśli', 'tego', 'które', 'także'],
+  nl: ['de', 'het', 'een', 'en', 'van', 'is', 'niet', 'dat', 'met', 'voor', 'ook', 'zijn', 'maar', 'als', 'wordt', 'deze', 'kan', 'naar', 'bij', 'dan'],
+  cs: ['a', 'je', 'se', 'na', 'to', 'že', 'jak', 'ale', 'pro', 'nebo', 'jsou', 'může', 'také', 'tento', 'když', 'jeho', 'které', 'být', 'aby', 'ještě'],
+  tr: ['ve', 'bir', 'bu', 'için', 'ile', 'de', 'da', 'ama', 'gibi', 'daha', 'var', 'olarak', 'çok', 'ne', 'her', 'kadar', 'sonra', 'değil', 'olan', 'ise'],
+  sv: ['och', 'att', 'det', 'är', 'en', 'som', 'för', 'inte', 'med', 'till', 'den', 'kan', 'har', 'ett', 'men', 'också', 'eller', 'från', 'när', 'vara'],
+  uk: ['і', 'та', 'що', 'це', 'не', 'як', 'для', 'він', 'вона', 'але', 'або', 'також', 'тільки', 'вже', 'якщо', 'його', 'цей', 'ця', 'бути', 'коли'],
+  ru: ['и', 'что', 'это', 'не', 'как', 'для', 'он', 'она', 'но', 'или', 'также', 'только', 'уже', 'если', 'его', 'этот', 'эта', 'быть', 'когда', 'чтобы'],
+};
+
+const LATIN_LANGUAGES = ['en', 'de', 'fr', 'es', 'it', 'pt', 'pl', 'nl', 'cs', 'tr', 'sv'];
+const CYRILLIC_LANGUAGES = ['uk', 'ru'];
+
+const countMatches = (text, pattern) => {
+  const matches = text.match(pattern);
+  return matches ? matches.length : 0;
+};
+
+const scoreStopwords = (words, languages) => {
+  const scores = {};
+  for (const language of languages) {
+    const list = new Set(STOPWORDS[language]);
+    let hits = 0;
+    for (const word of words) {
+      if (list.has(word)) hits += 1;
+    }
+    scores[language] = hits;
+  }
+  return scores;
+};
+
+const bestOf = (scores, fallback) => {
+  let best = fallback;
+  let bestScore = 0;
+  for (const [language, score] of Object.entries(scores)) {
+    if (score > bestScore) {
+      best = language;
+      bestScore = score;
+    }
+  }
+  return best;
+};
+
+const pickByMarkers = (text, markers) => {
+  for (const [language, pattern] of Object.entries(markers)) {
+    if (pattern.test(text)) return language;
+  }
+  return null;
+};
+
+/**
+ * @param {string} text
+ * @returns {{ language: string, script: string }} BCP-47 primary language subtag and the dominant script.
+ */
+export function detectTextLanguage(text) {
+  const source = typeof text === 'string' ? text : '';
+  const counts = SCRIPT_RANGES.map(([script, pattern]) => [script, countMatches(source, pattern)]);
+  const letters = counts.reduce((sum, [, count]) => sum + count, 0);
+  if (letters === 0) return { language: 'en', script: 'latin' };
+
+  // Kana settles Japanese even when Han dominates the character count.
+  const kana = counts.find(([script]) => script === 'kana')?.[1] ?? 0;
+  const han = counts.find(([script]) => script === 'han')?.[1] ?? 0;
+  if (kana > 0 && kana + han >= letters * 0.3) return { language: 'ja', script: 'kana' };
+  if (han > 0 && han >= letters * 0.3) return { language: 'zh', script: 'han' };
+
+  const [script] = counts.reduce((best, entry) => (entry[1] > best[1] ? entry : best));
+
+  if (script in SCRIPT_LANGUAGE) return { language: SCRIPT_LANGUAGE[script], script };
+
+  const words = source.toLowerCase().split(/[^\p{L}\p{M}']+/u).filter(Boolean);
+
+  if (script === 'cyrillic') {
+    const scores = scoreStopwords(words, CYRILLIC_LANGUAGES);
+    const ukMarkers = countMatches(source, /[іїєґ]/gi);
+    const ruMarkers = countMatches(source, /[ыэъё]/gi);
+    // Letters decide: the two alphabets differ in letters that occur in
+    // nearly every sentence. Function words only settle a text that shows
+    // neither set, and a text with no Russian-only letters is far more
+    // likely Ukrainian than the reverse, so that tie goes to Ukrainian.
+    if (ukMarkers !== ruMarkers) return { language: ukMarkers > ruMarkers ? 'uk' : 'ru', script };
+    if (scores.uk !== scores.ru) return { language: scores.uk > scores.ru ? 'uk' : 'ru', script };
+    return { language: ruMarkers > 0 ? 'ru' : 'uk', script };
+  }
+
+  const scores = scoreStopwords(words, LATIN_LANGUAGES);
+  const marked = pickByMarkers(source, LATIN_MARKERS);
+  // A characteristic letter outranks stopword counts unless another language
+  // clearly dominates the function words (a German text quoting "façade").
+  if (marked && scores[marked] * 2 >= scores[bestOf(scores, marked)]) {
+    return { language: marked, script };
+  }
+  return { language: bestOf(scores, 'en'), script };
+}
+
+/**
+ * Map a detected language onto the locales a voice list uses (`uk_UA`,
+ * `en_US`...). Returns the preferred locale prefixes in order.
+ * @param {string} language
+ * @returns {string[]}
+ */
+function localePrefixesForLanguage(language) {
+  const table = {
+    en: ['en_US', 'en_GB', 'en'],
+    uk: ['uk_UA', 'uk'],
+    ru: ['ru_RU', 'ru'],
+    de: ['de_DE', 'de'],
+    fr: ['fr_FR', 'fr_CA', 'fr'],
+    es: ['es_ES', 'es_MX', 'es'],
+    it: ['it_IT', 'it'],
+    pt: ['pt_BR', 'pt_PT', 'pt'],
+    pl: ['pl_PL', 'pl'],
+    nl: ['nl_NL', 'nl_BE', 'nl'],
+    cs: ['cs_CZ', 'cs'],
+    tr: ['tr_TR', 'tr'],
+    sv: ['sv_SE', 'sv'],
+    zh: ['zh_CN', 'zh_TW', 'zh_HK', 'zh'],
+    ja: ['ja_JP', 'ja'],
+    ko: ['ko_KR', 'ko'],
+    el: ['el_GR', 'el'],
+    ar: ['ar_001', 'ar_SA', 'ar'],
+    he: ['he_IL', 'he'],
+    th: ['th_TH', 'th'],
+    hi: ['hi_IN', 'hi'],
+  };
+  return table[language] ?? [language];
+}
+
+/**
+ * Choose a voice for a language from a `say`-style voice list.
+ * Prefers an enhanced/premium variant of a matching voice, then any voice of
+ * the exact locale, then any voice of the language. Returns null when the
+ * list has no voice for that language.
+ * @param {string} language
+ * @param {ReadonlyArray<{ name: string, locale: string }>} voices
+ * @returns {string | null}
+ */
+export function pickVoiceForLanguage(language, voices) {
+  const prefixes = localePrefixesForLanguage(language);
+  for (const prefix of prefixes) {
+    const matching = voices.filter((voice) => voice.locale === prefix || voice.locale.startsWith(`${prefix}_`) || (prefix === language && voice.locale.startsWith(`${language}_`)));
+    if (matching.length === 0) continue;
+    const enhanced = matching.find((voice) => /\((Enhanced|Premium)\)/i.test(voice.name));
+    return (enhanced ?? matching[0]).name;
+  }
+  return null;
+}
+
+/**
+ * Language of a voice, from its locale (`uk_UA` → `uk`).
+ * @param {string | null | undefined} locale
+ * @returns {string | null}
+ */
+export function languageOfLocale(locale) {
+  if (typeof locale !== 'string' || !locale) return null;
+  return locale.split(/[_-]/)[0].toLowerCase();
+}
diff --git a/packages/web/server/lib/tts/language-detect.test.js b/packages/web/server/lib/tts/language-detect.test.js
new file mode 100644
index 00000000..a8c0f2c3
--- /dev/null
+++ b/packages/web/server/lib/tts/language-detect.test.js
@@ -0,0 +1,76 @@
+import { describe, expect, it } from 'vitest';
+import { detectTextLanguage, languageOfLocale, pickVoiceForLanguage } from './language-detect.js';
+
+describe('detectTextLanguage', () => {
+  it.each([
+    ['en', 'The build is green and the tests pass, so you can merge this now.'],
+    ['uk', 'Привіт! Це тестове повідомлення, і воно написане українською мовою.'],
+    ['ru', 'Привет! Это тестовое сообщение, и оно написано на русском языке.'],
+    ['de', 'Die Änderung ist fertig und die Tests laufen ohne Fehler durch.'],
+    ['fr', 'La modification est prête et les tests passent sans erreur.'],
+    ['es', 'El cambio está listo y las pruebas pasan sin errores.'],
+    ['it', 'La modifica è pronta e i test passano senza errori.'],
+    ['pt', 'A alteração está pronta e os testes passam sem erros, você pode continuar.'],
+    ['pl', 'Zmiana jest gotowa i testy przechodzą bez błędów.'],
+    ['nl', 'De wijziging is klaar en de tests slagen zonder fouten.'],
+    ['cs', 'Změna je hotová a testy procházejí bez chyb.'],
+    ['tr', 'Değişiklik hazır ve testler hatasız geçiyor.'],
+    ['sv', 'Ändringen är klar och testerna går igenom utan fel.'],
+    ['zh', '修改已经完成，所有测试都通过了。'],
+    ['ja', '変更が完了し、すべてのテストに合格しました。'],
+    ['ko', '변경이 완료되었고 모든 테스트를 통과했습니다.'],
+  ])('detects %s', (language, text) => {
+    expect(detectTextLanguage(text).language).toBe(language);
+  });
+
+  it.each([
+    ['uk', 'Готово. Запушено.'],
+    ['uk', 'Все ок'],
+    ['uk', 'Добре, давай так зробимо'],
+    ['ru', 'Хорошо, давай так и сделаем'],
+    ['ru', 'Готово, всё запушено.'],
+  ])('tells short %s phrases apart by letters', (language, text) => {
+    expect(detectTextLanguage(text).language).toBe(language);
+  });
+
+  it('falls back to English for text without letters', () => {
+    expect(detectTextLanguage('1234 ... !!!').language).toBe('en');
+    expect(detectTextLanguage('').language).toBe('en');
+  });
+
+  it('does not let a single quoted foreign word flip an English paragraph', () => {
+    const text = 'The façade of the building is the part that you see from the street, and it is not the same as the interior.';
+    expect(detectTextLanguage(text).language).toBe('en');
+  });
+});
+
+describe('pickVoiceForLanguage', () => {
+  const voices = [
+    { name: 'Samantha', locale: 'en_US' },
+    { name: 'Daniel', locale: 'en_GB' },
+    { name: 'Lesya', locale: 'uk_UA' },
+    { name: 'Lesya (Enhanced)', locale: 'uk_UA' },
+    { name: 'Milena', locale: 'ru_RU' },
+    { name: 'Anna', locale: 'de_DE' },
+  ];
+
+  it('prefers the enhanced variant of a matching voice', () => {
+    expect(pickVoiceForLanguage('uk', voices)).toBe('Lesya (Enhanced)');
+  });
+
+  it('prefers the primary locale of a language', () => {
+    expect(pickVoiceForLanguage('en', voices)).toBe('Samantha');
+  });
+
+  it('returns null when no voice speaks the language', () => {
+    expect(pickVoiceForLanguage('ja', voices)).toBeNull();
+  });
+});
+
+describe('languageOfLocale', () => {
+  it('reads the language subtag', () => {
+    expect(languageOfLocale('uk_UA')).toBe('uk');
+    expect(languageOfLocale('en-GB')).toBe('en');
+    expect(languageOfLocale(null)).toBeNull();
+  });
+});
diff --git a/packages/web/server/lib/tts/routes.js b/packages/web/server/lib/tts/routes.js
index 5d2c4618..2f2074ff 100644
--- a/packages/web/server/lib/tts/routes.js
+++ b/packages/web/server/lib/tts/routes.js
@@ -2,6 +2,8 @@ import express from 'express';
 import { normalizeCustomOpenAIBaseURL } from './base-url.js';
 import { summarizeText, sanitizeForTTS, sanitizeForNote } from '../text/summarization.js';
 
+import { detectTextLanguage, languageOfLocale, pickVoiceForLanguage } from './language-detect.js';
+
 export function registerTtsRoutes(app, { sayTTSCapability }) {
   let ttsModulePromise = null;
   const getTtsModule = async () => {
@@ -154,7 +156,8 @@ export function registerTtsRoutes(app, { sayTTSCapability }) {
   // macOS 'say' command TTS speak endpoint
   app.post('/api/tts/say/speak', async (req, res) => {
     try {
-      const { text, voice = 'Samantha', rate = 200 } = req.body || {};
+      const { text, rate = 200, language, languageSample } = req.body || {};
+      let voice = typeof req.body?.voice === 'string' && req.body.voice.trim() ? req.body.voice.trim() : 'Samantha';
       
       if (!text || typeof text !== 'string' || !text.trim()) {
         return res.status(400).json({ error: 'Text is required' });
@@ -164,6 +167,23 @@ export function registerTtsRoutes(app, { sayTTSCapability }) {
       if (process.platform !== 'darwin') {
         return res.status(503).json({ error: 'macOS say command not available on this platform' });
       }
+
+      // `language: 'auto'`: keep the chosen voice while it speaks the text's
+      // language, otherwise switch to an installed voice that does. A
+      // language with no installed voice keeps the chosen voice — say still
+      // reads the text, just with an accent — rather than failing.
+      let resolvedLanguage = null;
+      if (language === 'auto') {
+        const capability = await sayTTSCapability;
+        const voices = Array.isArray(capability?.voices) ? capability.voices : [];
+        const sample = typeof languageSample === 'string' && languageSample.trim() ? languageSample.slice(0, 4000) : text;
+        resolvedLanguage = detectTextLanguage(sample).language;
+        const chosen = voices.find((entry) => entry.name === voice);
+        if (languageOfLocale(chosen?.locale) !== resolvedLanguage) {
+          const match = pickVoiceForLanguage(resolvedLanguage, voices);
+          if (match) voice = match;
+        }
+      }
       
       const { exec } = await import('child_process');
       const { promisify } = await import('util');
@@ -195,6 +215,8 @@ export function registerTtsRoutes(app, { sayTTSCapability }) {
       
       // Send audio response
       res.setHeader('Content-Type', 'audio/mp4');
+      res.setHeader('X-Speech-Voice', voice);
+      if (resolvedLanguage) res.setHeader('X-Speech-Language', resolvedLanguage);
       res.setHeader('Content-Length', audioBuffer.length);
       res.send(audioBuffer);
       
diff --git a/packages/web/server/lib/tts/routes.test.js b/packages/web/server/lib/tts/routes.test.js
index f4940265..fce960a4 100644
--- a/packages/web/server/lib/tts/routes.test.js
+++ b/packages/web/server/lib/tts/routes.test.js
@@ -33,6 +33,32 @@ describe('tts routes', () => {
     });
   });
 
+  it('switches the say voice to the language of the text when asked to', async () => {
+    const capability = Promise.resolve({
+      available: true,
+      voices: [
+        { name: 'Samantha', locale: 'en_US' },
+        { name: 'Lesya', locale: 'uk_UA' },
+        { name: 'Lesya (Enhanced)', locale: 'uk_UA' },
+      ],
+    });
+    const app = createApp(capability);
+    const response = await request(app)
+      .post('/api/tts/say/speak')
+      .send({ text: 'Привіт! Це відповідь українською мовою, і вона досить довга.', voice: 'Samantha', language: 'auto' });
+
+    // On macOS the route synthesizes; elsewhere it refuses before running say.
+    // Either way the chosen voice must be the Ukrainian one when the platform
+    // allows the request to proceed.
+    if (process.platform === 'darwin') {
+      expect(response.status).toBe(200);
+      expect(response.headers['x-speech-voice']).toBe('Lesya (Enhanced)');
+      expect(response.headers['x-speech-language']).toBe('uk');
+    } else {
+      expect(response.status).toBe(503);
+    }
+  });
+
   it('returns local note fallback while model summarization is retired', async () => {
     const response = await request(createApp())
       .post('/api/text/summarize')