Web/JavaScript/Reference/Global objects/Intl

The Intl object is the namespace for the ECMAScript Internationalization API, which provides language sensitive string comparison, number formatting, and date and time formatting. The Intl object provides access to several constructors as well as functionality common to the internationalization constructors and other language sensitive functions.

Constructor properties

Intl.Collator(): Constructor for collators, which are objects that enable language-sensitive string comparison.
Intl.DateTimeFormat(): Constructor for objects that enable language-sensitive date and time formatting.
Intl.DisplayNames(): Constructor for objects that enable the consistent translation of language, region and script display names.
Intl.ListFormat(): Constructor for objects that enable language-sensitive list formatting.
Intl.Locale(): Constructor for objects that represents a Unicode locale identifier.
Intl.NumberFormat(): Constructor for objects that enable language-sensitive number formatting.
Intl.PluralRules(): Constructor for objects that enable plural-sensitive formatting and language-specific rules for plurals.
Intl.RelativeTimeFormat(): Constructor for objects that enable language-sensitive relative time formatting.

Static methods

Intl.getCanonicalLocales(): Returns canonical locale names.

Locale identification and negotiation

The internationalization constructors as well as several language sensitive methods of other constructors (listed under See also) use a common pattern for identifying locales and determining the one they will actually use: they all accept locales and options arguments, and negotiate the requested locale(s) against the locales they support using an algorithm specified in the options.localeMatcher property.

locales argument

The locales argument requests that a particular locale (or a locale from a list of them) be considered for use in a given operation. A single locale may be specified by either an Intl.Locale object or a string that is a Unicode BCP 47 locale identifier. Multiple locales may be specified (and a best-supported locale determined by evaluating each of them in order and comparing against the locales supported by the implementation) by passing an array (or array-like object, with a length property and corresponding indexed elements) whose elements are either Intl.Locale objects or values that convert to Unicode BCP 47 locale identifier strings. If the locales argument is not provided or is undefined, the runtime's default locale is used.

A Unicode BCP 47 locale identifier consists of

a language code,
(optionally) a script code,
(optionally) a region (or country) code,
(optionally) one or more variant codes, and
(optionally) one or more extension sequences,

with all present components separated by hyphens. Locale identifiers are case-insensitive ASCII. However, it's conventional to use title case (first letter capitalized, successive letters lower case) for script code, upper case for region codes, and lower case for everything else. For example:

"hi": Hindi (language)
"de-AT": German (language) as used in Austria (region)
"zh-Hans-CN": Chinese (language) written in simplified characters (script) as used in China (region)
"en-emodeng": English (language) in the "Early modern English" dialect (variant)

The subtags identifying languages, scripts, regions (including countries), and (rarely used) variants in Unicode BCP 47 locale identifiers are registered in the IANA Language Subtag Registry. This registry is periodically updated over time, and implementations may not always be up to date, so be careful not to rely too much on tags being universally supported.

BCP 47 also allows for extensions, each consisting of a single digit or letter (other than "x") and one or more two- to eight-letter or digit tags, all separated by hyphens. JavaScript internationalization functions use the "u" (Unicode) extension, which can be used to request additional customization of Collator, NumberFormat, or DateTimeFormat objects. Examples:

"de-DE-u-co-phonebk": Use the phonebook variant of the German sort order, which interprets umlauted vowels as corresponding character pairs: ä → ae, ö → oe, ü → ue.
"th-TH-u-nu-thai": Use Thai digits (๐, ๑, ๒, ๓, ๔, ๕, ๖, ๗, ๘, ๙) in number formatting.
"ja-JP-u-ca-japanese": Use the Japanese calendar in date and time formatting, so that 2013 is expressed as the year 25 of the Heisei period, or 平成25.
"en-GB-u-ca-islamic": use British English with the Islamic (Hijri) calendar, where the Gregorian date 14 October, 2017 is the Hijri date 24 Muharram, 1439.

Other BCP 47 extension tags can be found in the Unicode CLDR Project.

Finally, an extension using the letter "x" may appear, followed by one or one- to eight-letter or digit tags. This extension allows applications to encode information for their own private use, that will be ignored by all Intl operations.

Locale negotiation

The list of locales specified by the locales argument, after Unicode extensions have been removed from them, is interpreted as a prioritized request from the application. The runtime compares it against the locales it has available and picks the best one available. Two matching algorithms exist: the "lookup" matcher follows the Lookup algorithm specified in BCP 47; the "best fit" matcher lets the runtime provide a locale that's at least, but possibly more, suited for the request than the result of the Lookup algorithm. If the application doesn't provide a locales argument, or the runtime doesn't have a locale that matches the request, then the runtime's default locale is used. The matcher can be selected using a property of the options argument (see below).

If the selected language tag had a Unicode extension substring, that extension is now used to customize the constructed object or the behavior of the function. Each constructor or function supports only a subset of the keys defined for the Unicode extension, and the supported values often depend on the language tag. For example, the "co" key (collation) is only supported by Collator, and its "phonebk" value is only supported for German.

options argument

The options argument must be an object with properties that vary between constructors and functions. If the options argument is not provided or is undefined, default values are used for all properties.

One property is supported by all language sensitive constructors and functions: The localeMatcher property, whose value must be a string "lookup" or "best fit" and which selects one of the locale matching algorithms described above.

Examples

Formatting dates and numbers

You can use Intl to format dates and numbers in a form that's conventional for a specific language and region:

const count = 26254.39;
const date = new Date("2012-05-24");

function log(locale) {
  console.log(
    `${new Intl.DateTimeFormat(locale).format(date)} ${new Intl.NumberFormat(locale).format(count)}`
  );
}

log("en-US");
// expected output: 5/24/2012 26,254.39

log("de-DE");
// expected output: 24.5.2012 26.254,39

Specifications

Specification
ECMAScript Internationalization API (ECMA-402)The definition of 'Intl' in that specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`Intl`	Chrome Full support 24	Edge Full support 12	Firefox Full support 29	IE Full support 11	Opera Full support 15	Safari Full support 10	WebView Android Full support 4.4	Chrome Android Full support 25	Firefox Android Full support 56	Opera Android Full support 14	Safari iOS Full support 10	Samsung Internet Android Full support 1.5	nodejs Full support 0.12 Notes' Full support 0.12 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. When other locales are specified, the `Intl` APIs silently fall back to `en-US`. To make full ICU (locale) data available for versions prior to 13, see Node.js documentation on the `--with-intl` option and how to provide the data.
`Collator`	Chrome Full support 24	Edge Full support 12	Firefox Full support 29	IE Full support 11	Opera Full support 15	Safari Full support 10	WebView Android Full support 4.4	Chrome Android Full support 25	Firefox Android Full support 56	Opera Android Full support 14	Safari iOS Full support 10	Samsung Internet Android Full support 1.5	nodejs Full support 0.12 Notes' Full support 0.12 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. See the `Collator()` constructor for more details.
`DateTimeFormat`	Chrome Full support 24	Edge Full support 12	Firefox Full support 29	IE Full support 11	Opera Full support 15	Safari Full support 10	WebView Android Full support 4.4	Chrome Android Full support 25	Firefox Android Full support 56	Opera Android Full support 14	Safari iOS Full support 10	Samsung Internet Android Full support 1.5	nodejs Full support 0.12 Notes' Full support 0.12 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. See the `DateTimeFormat()` constructor for more details.
`DisplayNames`	Chrome Full support 81	Edge Full support 81	Firefox No support No	IE No support No	Opera Full support 68	Safari No support No	WebView Android Full support 81	Chrome Android Full support 81	Firefox Android No support No	Opera Android Full support 58	Safari iOS No support No	Samsung Internet Android No support No	nodejs Full support 14.0.0
`getCanonicalLocales`	Chrome Full support 54	Edge Full support 16	Firefox Full support 48	IE No support No	Opera No support No	Safari Full support 11	WebView Android No support No	Chrome Android No support No	Firefox Android Full support 56	Opera Android No support No	Safari iOS Full support 11	Samsung Internet Android No support No	nodejs Full support 7.0.0
`ListFormat` Experimental'	Chrome Full support 72	Edge No support No	Firefox Full support 78	IE No support No	Opera Full support 60	Safari No support No	WebView Android Full support 72	Chrome Android Full support 72	Firefox Android No support No	Opera Android Full support 51	Safari iOS No support No	Samsung Internet Android No support No	nodejs Full support 12.0.0 Notes' Full support 12.0.0 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. See the `ListFormat()` constructor for more details.
`Locale`	Chrome Full support 74	Edge Full support 79	Firefox Full support 75	IE No support No	Opera Full support 62	Safari Full support 14 Notes' Full support 14 Notes' Notes' Safari 14 Technology Preview 107-111 returns a string instead of a Locale object from the minimize and maximize methods.	WebView Android Full support 74	Chrome Android Full support 74	Firefox Android No support No	Opera Android Full support 53	Safari iOS Full support 14 Notes' Full support 14 Notes' Notes' Safari 14 Technology Preview 107-111 returns a string instead of a Locale object from the minimize and maximize methods.	Samsung Internet Android Full support 11.0	nodejs Full support 12.0.0 Notes' Full support 12.0.0 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. See the `Locale()` constructor for more details.
`NumberFormat`	Chrome Full support 24	Edge Full support 12	Firefox Full support 29	IE Full support 11	Opera Full support 15	Safari Full support 10	WebView Android Full support 4.4	Chrome Android Full support 25	Firefox Android Full support 56	Opera Android Full support 14	Safari iOS Full support 10	Samsung Internet Android Full support 1.5	nodejs Full support 0.12 Notes' Full support 0.12 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. See the `NumberFormat()` constructor for more details.
`PluralRules`	Chrome Full support 63	Edge Full support 18	Firefox Full support 58	IE No support No	Opera Full support 50	Safari Full support 13	WebView Android Full support 63	Chrome Android Full support 63	Firefox Android Full support 58	Opera Android Full support 46	Safari iOS Full support 13	Samsung Internet Android Full support 8.0	nodejs Full support 10.0.0 Notes' Full support 10.0.0 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. See the `PluralRules()` constructor for more details.
`RelativeTimeFormat`	Chrome Full support 71	Edge Full support 79	Firefox Full support 65	IE No support No	Opera Full support 58	Safari Full support 14	WebView Android Full support 71	Chrome Android Full support 71	Firefox Android Full support 65	Opera Android Full support 50	Safari iOS Full support 14	Samsung Internet Android Full support 10.0	nodejs Full support 12.0.0 Notes' Full support 12.0.0 Notes' Notes' Before version 13.0.0, only the locale data for `en-US` is available by default. See the `RelativeTimeFormat()` constructor for more details.

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.
See implementation notes.': See implementation notes.