tabs.detectLanguage()

Detects the primary language of the content in a tab, using the Compact Language Detector (CLD).

This is an asynchronous function that returns a Promise.

Syntax

var detecting = browser.tabs.detectLanguage(
  tabId                   // optional integer
)

Parameters

tabIdOptional
integer. Defaults to the active tab of the current window.

Return value

A Promise that will be fulfilled with a string representing an ISO language code such as en or fr. For a complete list of languages supported by this method, see the CLD2 README. For an unknown language, "und" will be returned (but see bug 1288263). If any error occurs the promise will be rejected with an error message.

Browser compatibility

Chrome Edge Firefox Firefox for Android Opera
Basic support Yes Yes 45.0 No 33

Examples

Detect and log the language of the active tab when the user clicks a browser action:

function onLanguageDetected(lang) {
  console.log(`Language is: ${lang}`);
}

function onError(error) {
  console.log(`Error: ${error}`);
}

browser.browserAction.onClicked.addListener(function() {
  var detecting = browser.tabs.detectLanguage();
  detecting.then(onLanguageDetected, onError);
});

Detect and log the language of every open tab when the user clicks a browser action (note that this example requires the "tabs" permission):

function onLanguageDetected(url, lang) {
  console.log(`Language in ${url} is: ${lang}`);
}

function onError(error) {
  console.log(`Error: ${error}`);
}

function detectLanguages(tabs) {
  for (tab of tabs) {
    var onFulfilled = onLanguageDetected.bind(null, tab.url);
    var detecting = browser.tabs.detectLanguage(tab.id);
    detecting.then(onFulfilled, onError);
  }
}

browser.browserAction.onClicked.addListener(function() {
  var querying = browser.tabs.query({});
  querying.then(detectLanguages, onError);
});

Acknowledgements

This API is based on Chromium's chrome.tabs API. This documentation is derived from tabs.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.

Document Tags and Contributors

 Contributors to this page: wbamberg, Makyen
 Last updated by: wbamberg,