Intl.getCanonicalLocales()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2017.

The Intl.getCanonicalLocales() static method returns an array containing the canonical locale names. Duplicates will be omitted and elements will be validated as structurally valid language tags.

Try it

console.log(Intl.getCanonicalLocales("EN-US"));
// Expected output: Array ["en-US"]

console.log(Intl.getCanonicalLocales(["EN-US", "Fr"]));
// Expected output: Array ["en-US", "fr"]

try {
  Intl.getCanonicalLocales("EN_US");
} catch (err) {
  console.log(err.toString());
  // Expected output (Firefox/Safari): RangeError: invalid language tag: "EN_US"
  // Expected output (Chrome): RangeError: Incorrect locale information provided
}

Syntax

js
Intl.getCanonicalLocales(locales)

Parameters

locales

A list of String values for which to get the canonical locale names.

Return value

An array containing the canonical locale names.

Examples

Using getCanonicalLocales

js
Intl.getCanonicalLocales("EN-US"); // ["en-US"]
Intl.getCanonicalLocales(["EN-US", "Fr"]); // ["en-US", "fr"]

Intl.getCanonicalLocales("EN_US");
// RangeError:'EN_US' is not a structurally valid language tag

Specifications

Specification
ECMAScript® 2025 Internationalization API Specification
# sec-intl.getcanonicallocales

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
getCanonicalLocales

Legend

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Full support
Full support

See also