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Intl.Collator.prototype.compare()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨September 2017⁩.

The compare() method of Intl.Collator instances compares two strings according to the sort order of this collator object.

Try it

const enCollator = new Intl.Collator("en");
const deCollator = new Intl.Collator("de");
const svCollator = new Intl.Collator("sv");

console.log(enCollator.compare("z", "a") > 0);
// Expected output: true

console.log(deCollator.compare("z", "ä") > 0);
// Expected output: true

console.log(svCollator.compare("z", "ä") > 0);
// Expected output: false

Syntax

compare(string1, string2)

Parameters

string1, string2: The strings to compare against each other.

Return value

A number indicating how string1 and string2 compare to each other according to the sort order of this Intl.Collator object:

A negative value if string1 comes before string2;
A positive value if string1 comes after string2;
0 if they are considered equal.

Examples

Using compare for array sort

Use the compare function for sorting arrays. Note that the function is bound to the collator from which it was obtained, so it can be passed directly to Array.prototype.sort().

const a = ["Offenbach", "Österreich", "Odenwald"];
const collator = new Intl.Collator("de-u-co-phonebk");
a.sort(collator.compare);
console.log(a.join(", ")); // "Odenwald, Österreich, Offenbach"

Using compare for array search

Use the compare function for finding matching strings in arrays:

const a = ["Congrès", "congres", "Assemblée", "poisson"];
const collator = new Intl.Collator("fr", {
  usage: "search",
  sensitivity: "base",
});
const s = "congres";
const matches = a.filter((v) => collator.compare(v, s) === 0);
console.log(matches.join(", ")); // "Congrès, congres"

Specifications

Specification
ECMAScript® 2026 Internationalization API Specification> # sec-intl.collator.prototype.compare>

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
`compare`	24	12	29	15	10	25	56	14	10	1.5	4.4	10	1.0.0	1.8	0.12.0 Before version 13.0.0, only the locale data for `en-US` is available by default. See the `Collator()` constructor for more details.