Intl.Locale.prototype.language

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2020.

The language accessor property of Intl.Locale instances returns the language associated with this locale.

Description

Language is one of the core attributes of a locale. The Unicode specification treats the language identifier of a locale as the language and the region together (to make a distinction between dialects and variations, e.g. British English vs. American English). The language property of a Intl.Locale returns strictly the locale's language subtag. The language property's value is set at construction time, either through the language subtag (first part) of the locale identifier or through the language option of the Intl.Locale() constructor. The latter takes priority if they are both present.

The set accessor of language is undefined. You cannot change this property directly.

Examples

Like other locale subtags, the language can be added to the Intl.Locale object via the locale string, or a configuration object argument to the constructor.

Setting the language via the locale string

In order to be a valid Unicode locale identifier, a string must start with the language subtag. The main argument to the Intl.Locale() constructor must be a valid Unicode locale identifier, so whenever the constructor is used, it must be passed an identifier with a language subtag.

js
const locale = new Intl.Locale("en-Latn-US");
console.log(locale.language); // Prints "en"

Overriding language via the configuration object argument

While the language subtag must be specified, the Intl.Locale() constructor has an optional configuration object argument, which can override the language subtag.

js
const locale = new Intl.Locale("en-Latn-US", { language: "es" });
console.log(locale.language); // Prints "es"

Specifications

Specification
ECMAScript® 2025 Internationalization API Specification
# sec-Intl.Locale.prototype.language

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
language

Legend

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Full support
Full support

See also