Web/API/URLSearchParams/append

The append() method of the URLSearchParams interface appends a specified key/value pair as a new search parameter.

As shown in the example below, if the same key is appended multiple times it will appear in the parameter string multiple times for each value.

Note: This feature is available in Web Workers.

Syntax

URLSearchParams.append(name, value)

Parameters

name: The name of the parameter to append.
value: The value of the parameter to append.

Return value

Void.

Examples

let url = new URL('https://example.com?foo=1&bar=2');
let params = new URLSearchParams(url.search.slice(1));

//Add a second foo parameter.
params.append('foo', 4);
//Query string is now: 'foo=1&bar=2&foo=4'

Specifications

Specification	Status	Comment
URLThe definition of 'append()' in that specification.	Living Standard	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`append`	Chrome Full support 49	Edge Full support 17	Firefox Full support 29	IE No support No	Opera Full support 36	Safari Full support 10.1	WebView Android Full support 49	Chrome Android Full support 49	Firefox Android Full support 29	Opera Android Full support 36	Safari iOS Full support 10.3	Samsung Internet Android Full support 5.0

Legend

Full support: Full support
No support: No support