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Intl.ListFormat.prototype.formatToParts()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨April 2021⁩.

The formatToParts() method of Intl.ListFormat instances returns an array of objects representing each part of the formatted string that would be returned by format(). It is useful for building custom strings from the locale-specific tokens.

Try it

const vehicles = ["Motorcycle", "Bus", "Car"];

const formatterEn = new Intl.ListFormat("en", {
  style: "long",
  type: "conjunction",
});

const formatterFr = new Intl.ListFormat("fr", {
  style: "long",
  type: "conjunction",
});

const partValuesEn = formatterEn.formatToParts(vehicles).map((p) => p.value);
const partValuesFr = formatterFr.formatToParts(vehicles).map((p) => p.value);

console.log(partValuesEn);
// Expected output: "["Motorcycle", ", ", "Bus", ", and ", "Car"]"
console.log(partValuesFr);
// Expected output: "["Motorcycle", ", ", "Bus", " et ", "Car"]"

Syntax

formatToParts(list)

Parameters

list: An iterable object, such as an Array, containing strings. Omitting it results in formatting the empty array, which could be slightly confusing, so it is advisable to always explicitly pass a list.

Return value

An Array of objects containing the formatted list in parts. Each object has two properties, type and value, each containing a string. The string concatenation of value, in the order provided, will result in the same string as format(). The type may be one of the following:

literal: Any string that's a part of the format pattern; for example ", ", ", and", etc.
element: An element of the list, exactly as provided.

Examples

Using formatToParts()

const fruits = ["Apple", "Orange", "Pineapple"];
const myListFormat = new Intl.ListFormat("en-GB", {
  style: "long",
  type: "conjunction",
});

console.table(myListFormat.formatToParts(fruits));
// [
//  { "type": "element", "value": "Apple" },
//  { "type": "literal", "value": ", " },
//  { "type": "element", "value": "Orange" },
//  { "type": "literal", "value": " and " },
//  { "type": "element", "value": "Pineapple" }
// ]

Specifications

Specification
ECMAScript® 2026 Internationalization API Specification> # sec-Intl.ListFormat.prototype.formatToParts>

Browser compatibility

	Desktop					Mobile							Server
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS	Bun	Deno	Node.js
`formatToParts`	72	79	78	60	14.1 Only available on macOS Big Sur (11) and above.	72	79	51	14.5	11.0	72	14.5	1.0.3	1.8	12.0.0 Before version 13.0.0, only the locale data for `en-US` is available by default. See the `ListFormat()` constructor for more details.