Navigator: languages property

The languages read-only property of the Navigator interface returns an array of strings representing the user’s preferred languages. The language is described using a BCP 47 language tag. In the returned array they are ordered by preference with the most preferred language first.

The value of navigator.language is the first element of the returned array.

When its value changes, as the user’s preferred languages are changed a languagechange event is fired on the Window object.

The Accept-Language HTTP header in every HTTP request from the user’s browser generally lists the same locales as the navigator.languages property, with decreasing q values (quality values). Some browsers (Chrome and Safari) add language-only fallback tags in Accept-Language—for example, en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7 when navigator.languages is ["en-US", "zh-CN"]. For privacy purposes (reducing fingerprinting), both Accept-Language and navigator.languages may not include the full list of user preferences, such as in Safari (always) and Chrome’s incognito mode, where only one language is listed.

Value

An array of strings.

Examples

Listing the contents of navigator.language and navigator.languages

navigator.language; // "en-US"
navigator.languages; // ["en-US", "zh-CN", "ja-JP"]

Using Intl constructors to do language-specific formatting, with fallback

The array of language identifiers contained in navigator.languages can be passed directly to the Intl constructors to implement preference-based fallback selection of locales, where the first entry in the list that matches a locale supported by Intl is used:

const date = new Date("2012-05-24");

const formattedDate = new Intl.DateTimeFormat(navigator.languages).format(date);

Specifications

Browser compatibility

See also

• language
• navigator
• languagechange event
• Intl