Text To Speech

pub package

A flutter text to speech plugin (Swift,Kotlin)

Features

  • x Android, iOS, Web, Windows & macOS
    • x speak
    • x stop
    • x get languages
    • x set language
    • x set speech rate
    • x set speech volume
    • x set speech pitch
    • x get voices
    • x set voice
  • x Android, iOS, Web & macOS
    • x is language available
  • x Android, iOS, Web
    • x speech marks (requires iOS 7+, Android 26+, and default voice engine for web)
  • x Android, iOS
    • x synthesize to file (requires iOS 13+)
  • x Android, iOS, Web, & Windows
    • x pause
  • x Android
    • x set silence
    • x is language installed
    • x are languages installed
    • x get engines
    • x set engine
    • x get default engine
    • x get default voice
    • x set queue mode
    • x get max speech input length
  • x iOS
    • x set shared instance
    • x set audio session category

Usage

macOS

OSX version: 10.15

Example App from the macOS_app branch

Web

Website from the example directory.

Progress updates on Web

Progress updates are only supported for native speech synsthesis. Use the default engine to ensure support for progress updates. Chromium#41195426

Android

Change the minimum Android sdk version to 21 (or higher) in your android/app/build.gradle file.

minSdkVersion 21

Update the Kotlin Gradle Plugin Version

Change the verision of the Kotlin Gradle plugin to 1.9.10.
If your project was created with a version of Flutter before 3.19, go to the android/build.gradle file and update the ext.kotlin_version:

ext.kotlin_version = '1.9.10'

Otherwise go to android/settings.gradle and update the verion of the plugin org.jetbrains.kotlin.android:

id "org.jetbrains.kotlin.android" version "1.9.10" apply false

Apps targeting Android 11 that use text-to-speech should declare TextToSpeech.Engine.INTENT_ACTION_TTS_SERVICE in the queries elements of their manifest.

<queries>
  <intent>
    <action android:name="android.intent.action.TTS_SERVICE" />
  </intent>
</queries>

Pausing on Android

Android TTS does not support the pause function natively, so we have implemented a work around. We utilize the native onRangeStart() method to determine the index of start when pause is invoked. We use that index to create a new text the next time speak is invoked. Due to using onRangeStart(), pause works on SDK versions >= 26. Also, if using start and end offsets inside of setProgressHandler(), you'll need to keep a track of them if using pause since they will update once the new text is created when speak is called after being paused.

await flutterTts.pause()

iOS

There's a known issue with integrating plugins that use Swift into a Flutter project created with the Objective-C template. Flutter#16049

Example

To use this plugin :

  dependencies:
    flutter:
      sdk: flutter
    flutter_tts:
  • instantiate FlutterTts
FlutterTts flutterTts = FlutterTts();

To set shared audio instance (iOS only):

await flutterTts.setSharedInstance(true);

To set audio category and options with optional mode (iOS only). The following setup allows background music and in-app audio session to continue simultaneously:

await flutterTts.setIosAudioCategory(IosTextToSpeechAudioCategory.ambient,
     [
          IosTextToSpeechAudioCategoryOptions.allowBluetooth,
          IosTextToSpeechAudioCategoryOptions.allowBluetoothA2DP,
          IosTextToSpeechAudioCategoryOptions.mixWithOthers
     ],
     IosTextToSpeechAudioMode.voicePrompt
);

To await speak completion.

await flutterTts.awaitSpeakCompletion(true);

To await synthesize to file completion.

await flutterTts.awaitSynthCompletion(true);

speak, stop, getLanguages, setLanguage, setSpeechRate, getVoices, setVoice, setVolume, setPitch, isLanguageAvailable, setSharedInstance

Future _speak() async{
    var result = await flutterTts.speak("Hello World");
    if (result == 1) setState(() => ttsState = TtsState.playing);
}

Future _stop() async{
    var result = await flutterTts.stop();
    if (result == 1) setState(() => ttsState = TtsState.stopped);
}

List<dynamic> languages = await flutterTts.getLanguages;

await flutterTts.setLanguage("en-US");

await flutterTts.setSpeechRate(1.0);

await flutterTts.setVolume(1.0);

await flutterTts.setPitch(1.0);

await flutterTts.isLanguageAvailable("en-US");

// iOS, Android and Web only
//see the "Pausing on Android" section for more info
await flutterTts.pause();

// iOS, macOS, and Android only
// The last parameter is an optional boolean value for isFullPath (defaults to false)
await flutterTts.synthesizeToFile("Hello World", Platform.isAndroid ? "tts.wav" : "tts.caf", false);

// Each voice is a Map containing at least these keys: name, locale
// - Windows (UWP voices) only: gender, identifier
// - iOS, macOS only: quality, gender, identifier
// - Android only: quality, latency, network_required, features 
List<Map> voices = await flutterTts.getVoices;

await flutterTts.setVoice({"name": "Karen", "locale": "en-AU"});
// iOS, macOS only
await flutterTts.setVoice({"identifier": "com.apple.voice.compact.en-AU.Karen"});

// iOS only
await flutterTts.setSharedInstance(true);

// Android only
await flutterTts.speak("Hello World", focus: true);

await flutterTts.setSilence(2);

await flutterTts.getEngines;

await flutterTts.getDefaultVoice;

await flutterTts.isLanguageInstalled("en-AU");

await flutterTts.areLanguagesInstalled(["en-AU", "en-US"]);

await flutterTts.setQueueMode(1);

await flutterTts.getMaxSpeechInputLength;

await flutterTts.setAudioAttributesForNavigation();

Listening for platform calls

flutterTts.setStartHandler(() {
  setState(() {
    ttsState = TtsState.playing;
  });
});

flutterTts.setCompletionHandler(() {
  setState(() {
    ttsState = TtsState.stopped;
  });
});

flutterTts.setProgressHandler((String text, int startOffset, int endOffset, String word) {
  setState(() {
    _currentWord = word;
  });
});

flutterTts.setErrorHandler((msg) {
  setState(() {
    ttsState = TtsState.stopped;
  });
});

flutterTts.setCancelHandler((msg) {
  setState(() {
    ttsState = TtsState.stopped;
  });
});

// Android, iOS and Web
flutterTts.setPauseHandler((msg) {
  setState(() {
    ttsState = TtsState.paused;
  });
});

flutterTts.setContinueHandler((msg) {
  setState(() {
    ttsState = TtsState.continued;
  });
});

Getting Started

For help getting started with Flutter, view our online documentation.

For help on editing plugin code, view the documentation.

Libraries

flutter_tts
flutter_tts_web
interop_types