Intl.Locale

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.

* Some parts of this feature may have varying levels of support.

TheIntl.Locale object is a standard built-in property of the Intl object that represents a Unicode locale identifier.

Try it

const korean = new Intl.Locale("ko", {  script: "Kore",  region: "KR",  hourCycle: "h23",  calendar: "gregory",});const japanese = new Intl.Locale("ja-Jpan-JP-u-ca-japanese-hc-h12");console.log(korean.baseName, japanese.baseName);// Expected output: "ko-Kore-KR" "ja-Jpan-JP"console.log(korean.hourCycle, japanese.hourCycle);// Expected output: "h23" "h12"

TheIntl.Locale object was created to allow for easier manipulation of Unicode locales. Unicode represents locales with a string, called alocale identifier. The locale identifier consists of alanguage identifier andextension tags. Language identifiers are the core of the locale, consisting oflanguage,script,region, andvariants subtags. Additional information about the locale is stored in the optionalextension tags. Extension tags hold information about locale aspects such as calendar type, clock type, and numbering system type.

Traditionally, the Intl API used strings to represent locales, just as Unicode does. This is a simple and lightweight solution that works well. Adding a Locale class, however, adds ease of parsing and manipulating the language, script, and region, as well as extension tags. The following properties ofIntl.Locale correspond to Unicode locale identifier subtags:

Property	Corresponding subtag
`language`	Language ID, first part
`script`	Language ID, part after`language`
`region`	Language ID, part after`script`
`variants`	Language ID, part after`region`
`calendar`	`ca` (extension)
`caseFirst`	`kf` (extension)
`collation`	`co` (extension)
`hourCycle`	`hc` (extension)
`numberingSystem`	`nu` (extension)
`numeric`	`kn` (extension)

The information above is exactly provided as-is when theLocale object is constructed, without consulting any external database. TheIntl.Locale object additionally provides some methods that return information about the locale's real-world information, such as available calendars, collations, and numbering systems.

Constructor

Intl.Locale(): Creates a newLocale object.

Instance properties

These properties are defined onIntl.Locale.prototype and shared by allIntl.Locale instances.

Intl.Locale.prototype.baseName: Returns basic, core information about theLocale in the form of a substring of the complete data string.
Intl.Locale.prototype.calendar: Returns the part of theLocale that indicates the Locale's calendar era.
Intl.Locale.prototype.caseFirst: Returns whether case is taken into account for the locale's collation rules.
Intl.Locale.prototype.collation: Returns the collation type for theLocale, which is used to order strings according to the locale's rules.
Intl.Locale.prototype.constructor: The constructor function that created the instance object. ForIntl.Locale instances, the initial value is theIntl.Locale constructor.
Intl.Locale.prototype.hourCycle: Returns the time keeping format convention used by the locale.
Intl.Locale.prototype.language: Returns the language associated with the locale.
Intl.Locale.prototype.numberingSystem: Returns the numeral system used by the locale.
Intl.Locale.prototype.numeric: Returns whether the locale has special collation handling for numeric characters.
Intl.Locale.prototype.region: Returns the region of the world (usually a country) associated with the locale.
Intl.Locale.prototype.script: Returns the script used for writing the particular language used in the locale.
Intl.Locale.prototype.variants: Returns the variants subtags (such as different orthographies) associated with the locale.
Intl.Locale.prototype[Symbol.toStringTag]: The initial value of the[Symbol.toStringTag] property is the string"Intl.Locale". This property is used inObject.prototype.toString().

Instance methods

Intl.Locale.prototype.getCalendars(): Returns anArray of available calendar identifiers, according to the locale's rules.
Intl.Locale.prototype.getCollations(): Returns anArray of the collation types for theLocale.
Intl.Locale.prototype.getHourCycles(): Returns anArray of hour cycle identifiers, indicating either the 12-hour clock ("h12"), the Japanese 12-hour clock ("h11"), the 24-hour clock ("h23"), or the unused format "h24".
Intl.Locale.prototype.getNumberingSystems(): Returns anArray of numbering system identifiers available according to the locale's rules.
Intl.Locale.prototype.getTextInfo(): Returns the part indicating the ordering of charactersltr (left-to-right) orrtl (right-to-left).
Intl.Locale.prototype.getTimeZones(): Returns anArray of time zone identifiers, associated with theLocale.
Intl.Locale.prototype.getWeekInfo(): ReturnsUTS 35's Week Elements according to the locale rules.
Intl.Locale.prototype.maximize(): Gets the most likely values for the language, script, and region of the locale based on existing values.
Intl.Locale.prototype.minimize(): Attempts to remove information about the locale that would be added by callingmaximize().
Intl.Locale.prototype.toString(): Returns the Locale's full locale identifier string.

Examples

Basic usage

At its very simplest, theIntl.Locale() constructor takes a locale identifier string as its argument:

const us = new Intl.Locale("en-US");

Using the Locale constructor with an options object

The constructor also takes an optional configuration object argument, which can contain any of several extension types. For example, set thehourCycle property of the configuration object to your desired hour cycle type, and then pass it into the constructor:

const us12hour = new Intl.Locale("en-US", { hourCycle: "h12" });console.log(us12hour.hourCycle); // Prints "h12"

Specifications

Specification
ECMAScript® 2026 Internationalization API Specification # locale-objects

Browser compatibility

Help improve MDN

Learn how to contribute

This page was last modified on⁨Jul 22, 2025⁩ byMDN contributors.

View this page on GitHub •Report a problem with this content

Movatterモバイル変換