flutter_native_speech_to_text 1.1.0

A Flutter plugin for native speech-to-text using Android's RecognizerIntent ACTION_RECOGNIZE_SPEECH and the browser's Web Speech API on web.

flutter_native_speech_to_text

A lightweight Flutter plugin for speech-to-text recognition leveraging Android's native RecognizerIntent.ACTION_RECOGNIZE_SPEECH and the browser's Web Speech API on web.

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Features

• 🎯 Native Android Integration: Direct access to Android's built-in RecognizerIntent.ACTION_RECOGNIZE_SPEECH dialog.
• 🌍 Web Support: Runs in Chrome, Edge and Safari through the Web Speech API with the same Dart API.
• ⚙️ Fully Configurable: Exposes all major RecognizerIntent extras as typed Dart parameters.
• 🌐 Multi-language Support: Specify custom language codes (e.g., en-US, bn-BD, es-ES).
• 📊 Detailed Results: Access primary transcription, alternate transcript hypotheses, and confidence scores.
• ⏱️ Silence & Length Controls: Fine-tune speech input minimum length and silence thresholds.
• 🛡️ Zero Bloat: Lightweight implementation using Android system speech services without heavy third-party models.

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Platform Support

Platform	Supported	Notes
Android	✅	Requires device with Google Play Services or Speech Recognizer installed (API 24+)
iOS	⚠️	Safe stub only: never crashes, reports a PLATFORM_NOT_SUPPORTED error instead (see iOS behaviour)
Web	✅	Uses the browser's Web Speech API (see Web behaviour)
Desktop	❌	Not currently supported

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Installation

Add flutter_native_speech_to_text to your pubspec.yaml:

dependencies:
  flutter_native_speech_to_text: ^1.0.0

Or run:

flutter pub add flutter_native_speech_to_text

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Android Setup

1. Permissions & Queries

Add the following permissions and <queries> declaration to your android/app/src/main/AndroidManifest.xml (inside the <manifest> tag):

<manifest xmlns:android="http://schemas.android.com/apk/res/android">

    <!-- Permissions required for speech recognition -->
    <uses-permission android:name="android.permission.RECORD_AUDIO" />
    <uses-permission android:name="android.permission.INTERNET" />

    <!-- Queries declaration for Android 11+ (API 30+) package visibility -->
    <queries>
        <intent>
            <action android:name="android.speech.action.RECOGNIZE_SPEECH" />
        </intent>
    </queries>

    <application ...>
        ...
    </application>
</manifest>

Note on Android 6.0+ (API 23+): Make sure your application requests the runtime RECORD_AUDIO permission before initiating speech recognition if needed, or handle permission callbacks accordingly.

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Usage

1. Check Availability

Before starting recognition, check if a speech recognizer service is available on the user's device:

import 'package:flutter_native_speech_to_text/flutter_native_speech_to_text.dart';

final bool isAvailable = await FlutterNativeSpeechToText.isAvailable();

if (!isAvailable) {
  print('Speech recognition is not available on this device.');
}

2. Start Speech Recognition

Invoke FlutterNativeSpeechToText.listen() to open Android's native speech recognition dialog:

try {
  final SpeechResult result = await FlutterNativeSpeechToText.listen(
    language: 'en-US',
    languageModel: 'free_form', // 'free_form' or 'web_search'
    prompt: 'Say something...',
    maxResults: 5,
    partialResults: true,
    confidenceScores: true,
    speechInputMinimumLengthMillis: 2000,
    speechInputCompleteSilenceLengthMillis: 1500,
    speechInputPossiblyCompleteSilenceLengthMillis: 500,
  );

  print('Top Result: ${result.recognizedText}');
  print('Alternatives: ${result.alternativeResults}');
  print('Confidence Scores: ${result.confidenceScores}');
} on SpeechToTextException catch (e) {
  print('Error code: ${e.code}, message: ${e.message}');
}

3. Stop or Cancel Recognition

// Stop listening
await FlutterNativeSpeechToText.stop();

// Cancel listening session
await FlutterNativeSpeechToText.cancel();

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API & Parameter Reference

FlutterNativeSpeechToText.listen() Parameters

Parameter	RecognizerIntent Equivalent	Type	Description
language	EXTRA_LANGUAGE	String?	Recognition language tag (e.g. 'en-US', 'bn-BD'). Defaults to 'bn-BD'.
languagePreference	EXTRA_LANGUAGE_PREFERENCE	String?	Preferred language for recognition.
languageModel	EXTRA_LANGUAGE_MODEL	String?	'free_form' (default) or 'web_search'.
prompt	EXTRA_PROMPT	String?	Prompt text displayed to the user in the system dialog.
maxResults	EXTRA_MAX_RESULTS	int?	Maximum number of alternative recognition results.
partialResults	EXTRA_PARTIAL_RESULTS	bool?	Request partial recognition results.
confidenceScores	EXTRA_CONFIDENCE_SCORES	bool?	Request confidence scores for transcriptions.
speechInputMinimumLengthMillis	EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS	int?	Minimum duration in milliseconds to consider speech input.
speechInputCompleteSilenceLengthMillis	EXTRA_SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS	int?	Silence duration to consider speech complete.
speechInputPossiblyCompleteSilenceLengthMillis	EXTRA_SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS	int?	Silence duration to consider speech possibly complete.
getAudio	EXTRA_GET_AUDIO	bool?	Whether to request recorded audio data.
getAudioFormat	EXTRA_GET_AUDIO_FORMAT	String?	MIME type format for requested audio (e.g., 'audio/AMR').
originatorPackage	EXTRA_ORIGINATOR_PKG	String?	Calling package name.
isEnable	N/A	bool	Set to false to disable recognition (throws error). Defaults to true.

Note: Unspecified parameters will use Android system defaults.

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Result Model (SpeechResult)

Property	Type	Description
recognizedText	String?	The most probable recognized text string.
alternativeResults	List<String>?	List of alternative transcription hypotheses.
confidenceScores	List<double>?	Confidence scores corresponding to alternative results (0.0 to 1.0).
isFinal	bool	Indicates whether the result is final.

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Error Codes

When a SpeechToTextException is thrown, the code property provides specific failure reasons:

Code	Reason
NO_RECOGNIZER	No speech recognizer service is installed or active on the device.
NO_CONTEXT	Android activity context was null or detached.
ALREADY_LISTENING	A speech recognition session is already in progress.
DISABLED	The isEnable flag was passed as false.
ERROR	An exception occurred while launching the intent.
PLATFORM_NOT_SUPPORTED	The method was called on iOS, which is not supported yet (no crash, just this error).
PERMISSION_DENIED	(Web) Microphone permission was denied.
NO_MICROPHONE	(Web) No usable microphone was found.
NETWORK	(Web) The browser's speech service could not be reached.
LANGUAGE_NOT_SUPPORTED	(Web) The requested language is not supported by the browser.
MISSING_PLUGIN	The native side of the plugin is not registered in the current binary (e.g. plugin missing from a release build).

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Web behaviour

On web the plugin uses the browser's Web Speech API. No setup or extra dependencies are needed - the same listen(), stop(), cancel() and isAvailable() calls work unchanged.

• Browser support: Chrome, Edge and Safari. Firefox does not implement speech recognition, so isAvailable() returns false and listen() throws NO_RECOGNIZER.
• Secure context: the page must be served over HTTPS (or localhost), and the user must grant microphone permission when prompted.
• Server-side recognition: Chrome sends audio to Google's servers, so an internet connection is required.
• Single utterance: like Android, listen() completes after one utterance (or when you call stop()); cancel() completes it with an empty result.
• Supported parameters: language / languagePreference (default bn-BD), partialResults (enables interim hypotheses internally), maxResults (alternatives count) and isEnable. Android-only options (prompt, silence lengths, getAudio, ...) are ignored.
• confidenceScores and alternativeResults are filled from the browser's result.

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iOS behaviour

The package ships with an iOS entry point purely so that iOS builds of your app link and run normally instead of crashing (a missing plugin registration on iOS causes MissingPluginException, and any native speech call would abort).

On iOS every call fails gracefully:

Call	iOS result
FlutterNativeSpeechToText.isAvailable()	returns false (so UIs can disable the mic button)
FlutterNativeSpeechToText.listen(...)	throws SpeechToTextException(code: 'PLATFORM_NOT_SUPPORTED')
FlutterNativeSpeechToText.stop() / .cancel()	throws SpeechToTextException(code: 'PLATFORM_NOT_SUPPORTED')

Nothing is executed natively on iOS - no microphone permission is requested, no Info.plist keys are required, and no Objective-C/Swift exception can escape. Errors are converted to a normal Dart exception and printed with debugPrint, so you can show and log them:

try {
  final result = await FlutterNativeSpeechToText.listen();
} on SpeechToTextException catch (e) {
  debugPrint('Speech error: ${e.message} (code: ${e.code})');
  ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text(e.message)));
}

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Example

For a complete working sample application, check out the example folder in this repository.

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License

This project is licensed under the MIT License - see the LICENSE file for details.