local_translation

On device translation and language detection for Flutter.

Platform support

iOS and macOS

Apple's Translation and NaturalLanguage frameworks.

  • isSupported() is true on iOS 18+ physical devices and macOS 15+. It is false on older OS versions and the iOS Simulator.
  • Translation may prompt the user to download language models.

Android

Android's TranslationManager and TextClassifier APIs.

  • isSupported() is true on Android 12+ when the device provides an on device TranslationService. This is mainly available on Pixel devices with Live Translate. Many emulators and OEM phones return false.
  • Language detection works on API 29+ even when translation is unavailable.
  • Language models are managed by the system. The first translation may trigger a download via the OEM translation service.

Call isSupported() before translate or translateBatch. Language detection can still run when translation is unavailable.

Supported languages

Pass BCP 47 language tags as sourceLanguage and targetLanguage.

Apple Translate languages

Translation uses the same languages as Apple's Translate app.

Language Tag
Arabic ar
Dutch nl
English (United Kingdom) en-GB
English (United States) en
French (France) fr
German (Germany) de
Hindi hi
Indonesian id
Italian (Italy) it
Japanese ja
Korean ko
Mandarin Chinese (China mainland) zh-Hans
Mandarin Chinese (Taiwan) zh-Hant
Polish pl
Portuguese (Brazil) pt-BR
Russian ru
Spanish (Spain) es
Thai th
Turkish tr
Ukrainian uk
Vietnamese vi

Not every source/target pair is supported. For example, translating between English variants or into the same language is rejected. Language models must be downloaded on the device before use (this is prompted when trying to translate a string for the first time). Apple may add languages in future iOS and macOS releases; see iOS feature availability and LanguageAvailability.

Android language pairs

Supported language pairs depend on the device's translation service. Use isSupported() to check availability. On Pixel devices, languages can be managed in Settings > System > Live Translate.

Usage

final translation = LocalTranslation();

if (!await translation.isSupported()) {
  return;
}

final detection = await translation.detectLanguage('Hallo Welt');

final detections = await translation.detectLanguages([
  'Hallo Welt',
  'Guten Morgen',
]);

final one = await translation.translate(
  'Hallo Welt',
  targetLanguage: 'en',
);

final many = await translation.translateBatch(
  ['Hallo Welt', 'Wie geht es dir?'],
  sourceLanguage: 'de',
  targetLanguage: 'en',
);

sourceLanguage is optional. When omitted, the plugin auto detects.

Regenerating Pigeon

dart run pigeon --input pigeons/local_translation_api.dart

Libraries

local_translation