JavaScript (ES2026) reference · String Methods

JavaScript String replace() Method

Replace the first match of a string or regex (every match with the g flag) with new text or a function's result.

JavaScript (ES2026) Since ES3

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Syntax

string.replace(pattern, replacement)

Parameter	Description
`pattern`	A string (first occurrence only) or a regular expression.
`replacement`	A string (may use `$1`, `$&`) or a function returning the replacement.

A new string.

First match vs all matchesTry it yourself

const s = "red, red, red";
console.log(s.replace("red", "blue"));
console.log(s.replace(/red/g, "blue"));

Output

blue, red, red
blue, blue, blue

Capture groups and a functionTry it yourself

console.log("2026-10-22".replace(/(\d+)-(\d+)-(\d+)/, "$3/$2/$1"));
console.log("price: 10".replace(/\d+/, (n) => n * 2));

Output

22/10/2026
price: 20

Version	Change
JavaScript ES3	Added

string.replaceAll() · Replace every occurrence of a string (or regex with the g flag) with new text, without writing a regex.
string.match() · Match the string against a regular expression and return the matches (all of them with the g flag) or null.
string.split() · Split a string into an array of substrings at each separator (a string or regex), with an optional limit.
JavaScript Strings · tutorial
JavaScript String Methods · tutorial