Intl.NumberFormat

Intl.NumberFormat()

Creates a new NumberFormat object.

Intl.NumberFormat.supportedLocalesOf()

Returns an array containing those of the provided locales that are supported without having to fall back to the runtime's default locale.

These properties are defined on Intl.NumberFormat.prototype and shared by all Intl.NumberFormat instances.

Intl.NumberFormat.prototype.constructor

The constructor function that created the instance object. For Intl.NumberFormat instances, the initial value is the Intl.NumberFormat constructor.

Intl.NumberFormat.prototype[@@toStringTag]

The initial value of the @@toStringTag property is the string "Intl.NumberFormat". This property is used in Object.prototype.toString().

Intl.NumberFormat.prototype.format()

Getter function that formats a number according to the locale and formatting options of this Intl.NumberFormat object.

Intl.NumberFormat.prototype.formatRange()

Getter function that formats a range of numbers according to the locale and formatting options of the Intl.NumberFormat object from which the method is called.

Intl.NumberFormat.prototype.formatRangeToParts()

Returns an Array of objects representing the range of number strings in parts that can be used for custom locale-aware formatting.

Intl.NumberFormat.prototype.formatToParts()

Returns an Array of objects representing the number string in parts that can be used for custom locale-aware formatting.

Intl.NumberFormat.prototype.resolvedOptions()

Returns a new object with properties reflecting the locale and collation options computed during initialization of the object.

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

const number = 3500;

console.log(new Intl.NumberFormat().format(number));
// '3,500' if in US English locale

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:

const number = 123456.789;

// German uses comma as decimal separator and period for thousands
console.log(new Intl.NumberFormat("de-DE").format(number));
// 123.456,789

// Arabic in most Arabic speaking countries uses real Arabic digits
console.log(new Intl.NumberFormat("ar-EG").format(number));
// ١٢٣٤٥٦٫٧٨٩

// India uses thousands/lakh/crore separators
console.log(new Intl.NumberFormat("en-IN").format(number));
// 1,23,456.789

// the nu extension key requests a numbering system, e.g. Chinese decimal
console.log(new Intl.NumberFormat("zh-Hans-CN-u-nu-hanidec").format(number));
// 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(new Intl.NumberFormat(["ban", "id"]).format(number));
// 123.456,789

The results can be customized using the options argument:

const number = 123456.789;

// request a currency format
console.log(
  new Intl.NumberFormat("de-DE", { style: "currency", currency: "EUR" }).format(
    number,
  ),
);
// 123.456,79 €

// the Japanese yen doesn't use a minor unit
console.log(
  new Intl.NumberFormat("ja-JP", { style: "currency", currency: "JPY" }).format(
    number,
  ),
);
// ￥123,457

// limit to three significant digits
console.log(
  new Intl.NumberFormat("en-IN", { maximumSignificantDigits: 3 }).format(
    number,
  ),
);
// 1,23,000

// Formatting with units
console.log(
  new Intl.NumberFormat("pt-PT", {
    style: "unit",
    unit: "kilometer-per-hour",
  }).format(50),
);
// 50 km/h

console.log(
  (16).toLocaleString("en-GB", {
    style: "unit",
    unit: "liter",
    unitDisplay: "long",
  }),
);
// 16 litres

For an exhaustive list of options, see the Intl.NumberFormat() constructor page.

• Intl
• A polyfill of Intl.NumberFormat in FormatJS