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  1. Web
  2. JavaScript
  3. Reference
  4. Standard built-in objects
  5. decodeURIComponent()

decodeURIComponent()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

ThedecodeURIComponent() function decodes a Uniform Resource Identifier (URI) component previously created byencodeURIComponent() or by a similar routine.

Try it

function containsEncodedComponents(x) {  // ie ?,=,&,/ etc  return decodeURI(x) !== decodeURIComponent(x);}console.log(containsEncodedComponents("%3Fx%3Dtest")); // ?x=test// Expected output: trueconsole.log(containsEncodedComponents("%D1%88%D0%B5%D0%BB%D0%BB%D1%8B")); // шеллы// Expected output: false

Syntax

js
decodeURIComponent(encodedURI)

Parameters

encodedURI

An encoded component of a Uniform Resource Identifier.

Return value

A new string representing the decoded version of the given encoded Uniform Resource Identifier (URI) component.

Exceptions

URIError

Thrown ifencodedURI contains a% not followed by two hexadecimal digits, or if the escape sequence does not encode a valid UTF-8 character.

Description

decodeURIComponent() is a function property of the global object.

decodeURIComponent() uses the same decoding algorithm as described indecodeURI(). It decodesall escape sequences, including those that are not created byencodeURIComponent, like-.!~*'().

Examples

Decoding a Cyrillic URL component

js
decodeURIComponent("JavaScript_%D1%88%D0%B5%D0%BB%D0%BB%D1%8B");// "JavaScript_шеллы"

Catching errors

js
try {  const a = decodeURIComponent("%E0%A4%A");} catch (e) {  console.error(e);}// URIError: malformed URI sequence

Decoding query parameters from a URL

decodeURIComponent() cannot be used directly to parse query parameters from a URL. It needs a bit of preparation.

js
function decodeQueryParam(p) {  return decodeURIComponent(p.replace(/\+/g, " "));}decodeQueryParam("search+query%20%28correct%29");// 'search query (correct)'

Specifications

Specification
ECMAScript® 2026 Language Specification
# sec-decodeuricomponent-encodeduricomponent

Browser compatibility

See also

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