The Intl.Locale.prototype.maximize() method gets the most likely values for the language, script, and region of the locale based on existing values.



Return value

A Locale instance whose baseName property returns the result of the Add Likely Subtags algorithm executed against locale.baseName.


Sometimes, it is convenient to be able to identify the most likely locale language identifier subtags based on an incomplete langauage ID. The Add Likely Subtags algorithm gives us this functionality. For instance, given the language ID "en", the algorithm would return "en-Latn-US", since English can only be written in the Latin script, and is most likely to be used in the United States, as it is the largest English-speaking country in the world. This functionality is provided to JavaScript programmers via the maximize() method. maximize() only affects the main subtags that comprise the language identifier: language, script, and region subtags. Other subtags after the "-u" in the locale indentifier are called extension subtags and are not affected by the maximize() method. Examples of these subtags include Locale.hourCycle, Locale.calendar, and Locale.numeric.


Using maximize

let myLocale = new Intl.Locale("fr", {hourCycle: "h24", calendar: "gregory"});
console.log(myLocale.baseName); // Prints "fr"
console.log(myLocale.toString()); // Prints "fr-u-ca-gregory-hc-h24"
let myLocMaximized = myLocale.maximize();

// Prints "fr-Latn-FR". The "Latn" and "FR" tags are added,
// since French is only written in the Latin script and is most likely to be spoken in France.

// Prints "fr-Latn-FR-u-ca-gregory-hc-h24". 
// Note that the extension tags (after "-u") remain unchanged.


ECMAScript Internationalization API (ECMA-402)

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
maximizeChrome Full support 74Edge Full support 79Firefox Full support 75IE No support NoOpera Full support 62Safari No support NoWebView Android Full support 74Chrome Android Full support 74Firefox Android No support NoOpera Android Full support 53Safari iOS No support NoSamsung Internet Android Full support 11.0nodejs Full support 12.0.0
Full support 12.0.0
Notes Before version 13.0.0, only the locale data for en-US is available by default. See the Locale() constructor for more details.


Full support  
Full support
No support  
No support
See implementation notes.
See implementation notes.

See also