decodeURIComponent()

The decodeURIComponent() function decodes a Uniform Resource Identifier (URI) component previously created by {{jsxref("encodeURIComponent()")}} or by a similar routine.

{{InteractiveExample("JavaScript Demo: decodeURIComponent()")}}

```js interactive-example 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")); // шеллы // Expected output: false

## Syntax

```js-nolint
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#

• {{jsxref("URIError")}}
• : Thrown if encodedURI 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 in {{jsxref("decodeURI()")}}. It decodes all escape sequences, including those that are not created by {{jsxref("encodeURIComponent")}}, like -.!~*'().

Examples#

Decoding a Cyrillic URL component#

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

Catching errors#

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.

function decodeQueryParam(p) {
  return decodeURIComponent(p.replace(/\+/g, " "));
}

decodeQueryParam("search+query%20%28correct%29");
// 'search query (correct)'

Specifications#

{{Specifications}}

Browser compatibility#

{{Compat}}

See also#

• {{jsxref("decodeURI")}}
• {{jsxref("encodeURI")}}
• {{jsxref("encodeURIComponent")}}