Number.prototype.toLocaleString()

The toLocaleString() method returns a string with a language-sensitive representation of this number.

Syntax

numObj.toLocaleString([locales [, options]])

Parameters

The locales and options arguments customize the behavior of the function and let applications specify the language whose formatting conventions should be used. In implementations, which ignore the locales and options arguments, the locale used and the form of the string returned are entirely implementation dependent.

See the Intl.NumberFormat() constructor for details on these parameters and how to use them.

Return value

A string with a language-sensitive representation of the given number.

Examples

Using toLocaleString

In basic use without specifying a locale, a formatted string in the default locale and with default options is returned.

var number = 3500;

console.log(number.toLocaleString()); // Displays "3,500" if in U.S. English locale

Checking for support for locales and options arguments

The locales and options arguments are not supported in all browsers yet. To check for support in ES5.1 and later implementations, the requirement that illegal language tags are rejected with a RangeError exception can be used:

function toLocaleStringSupportsLocales() {
  var number = 0;
  try {
    number.toLocaleString('i');
  } catch (e) {
    return e.name === 'RangeError';
  }
  return false;
}

Prior to ES5.1, implementations were not required to throw a range error exception if toLocaleString is called with arguments.

A check that works in all hosts, including those supporting ECMA-262 prior to ed 5.1, is to test for the features specified in ECMA-402 that are required to support regional options for Number.prototype.toLocaleString directly:

function toLocaleStringSupportsOptions() {
  return !!(typeof Intl == 'object' && Intl && typeof Intl.NumberFormat == 'function');
}

This tests for a global Intl object, checks that it's not null and that it has a NumberFormat property that is a function.

Using locales

This example shows some of the variations in localized number formats. In order to get the format of the language used in the user interface of your application, make sure to specify that language (and possibly some fallback languages) using the locales argument:

var number = 123456.789;

// German uses comma as decimal separator and period for thousands
console.log(number.toLocaleString('de-DE'));
// → 123.456,789

// Arabic in most Arabic speaking countries uses Eastern Arabic digits
console.log(number.toLocaleString('ar-EG'));
// → ١٢٣٤٥٦٫٧٨٩

// India uses thousands/lakh/crore separators
console.log(number.toLocaleString('en-IN'));
// → 1,23,456.789

// the nu extension key requests a numbering system, e.g. Chinese decimal
console.log(number.toLocaleString('zh-Hans-CN-u-nu-hanidec'));
// → 一二三,四五六.七八九

// when requesting a language that may not be supported, such as
// Balinese, include a fallback language, in this case Indonesian
console.log(number.toLocaleString(['ban', 'id']));
// → 123.456,789

Using options

The results provided by toLocaleString can be customized using the options argument:

var number = 123456.789;

// request a currency format
console.log(number.toLocaleString('de-DE', { style: 'currency', currency: 'EUR' }));
// → 123.456,79 €

// the Japanese yen doesn't use a minor unit
console.log(number.toLocaleString('ja-JP', { style: 'currency', currency: 'JPY' }))
// → ¥123,457

// limit to three significant digits
console.log(number.toLocaleString('en-IN', { maximumSignificantDigits: 3 }));
// → 1,23,000

// Use the host default language with options for number formatting
var num = 30000.65;
console.log(num.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}));
// → "30,000.65" where English is the default language, or
// → "30.000,65" where German is the default language, or
// → "30 000,65" where French is the default language

Performance

When formatting large numbers of numbers, it is better to create a NumberFormat object and use the function provided by its NumberFormat.format property.

Specifications

Specification
ECMAScript Latest Draft (ECMA-262)
The definition of 'Number.prototype.toLocaleString' in that specification.
ECMAScript Internationalization API 4.0 (ECMA-402)
The definition of 'Number.prototype.toLocaleString' in that specification.

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
toLocaleStringChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 5Opera Full support 4Safari Full support 1WebView Android Full support 1Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support 10.1Safari iOS Full support 1Samsung Internet Android Full support 1.0nodejs Full support Yes
localesChrome Full support 24Edge Full support 12Firefox Full support 29IE Full support 11Opera Full support 15Safari Full support 10WebView Android Full support 4.4Chrome Android Full support 26Firefox Android Full support 56Opera Android Full support 14Safari iOS Full support 10Samsung Internet Android Full support 1.5nodejs Full support Yes
optionsChrome Full support 24Edge Full support 12Firefox Full support 29IE Full support 11Opera Full support 15Safari Full support 10WebView Android Full support 4.4Chrome Android Full support 26Firefox Android Full support 56Opera Android Full support 14Safari iOS Full support 10Samsung Internet Android Full support 1.5nodejs Full support Yes

Legend

Full support  
Full support

See also