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decodeURIComponent()

Baseline Widely available

This feature is well established and works across many devices and browser versions. Its been available across browsers since 2015 7.

decodeURIComponent() encodeURIComponent Uniform Resource Identifier(URI) .

In this article

function containsEncodedComponents(x) {
  // ie ?,=,&,/ etc
  return decodeURI(x) !== decodeURIComponent(x);
}

console.log(containsEncodedComponents("%3Fx%3Dtest")); // ?x=test
// Expected output: true

console.log(containsEncodedComponents("%D1%88%D0%B5%D0%BB%D0%BB%D1%8B")); // 
// Expected output: false

js
decodeURIComponent(encodedURI);

encodedURI

Uniform Resource Identifier(URI) .

.

URIError ( " malformed URI sequence ") .

URI ( ) .

URL

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

Specification
ECMAScript 2027 LanguageSpecification
# sec-decodeuricomponent-encodeduricomponent

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