Functions to internationalize your extension. You can use these APIs to get localized strings from locale files packaged with your extension, find out the browser's current language, and find out the value of its Accept-Language header.

See the Internationalization page for a guide on using this API.



A language tag such as "en-US" or "fr".



Gets the accept-languages of the browser. This is different from the locale used by the browser. To get the locale, use i18n.getUILanguage.


Gets the localized string for the specified message.


Gets the UI language of the browser. This is different from i18n.getAcceptLanguages which returns the preferred user languages.


Detects the language of the provided text using the Compact Language Detector.

Browser compatibility

BCD tables only load in the browser

Example extensions

Note: This API is based on Chromium's chrome.i18n API. This documentation is derived from i18n.json in the Chromium code.

Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.

See also