URLSearchParams: append() method

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.

Note: This feature is available in Web Workers.

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.

Syntax

js
append(name, value)

Parameters

name

The name of the parameter to append.

value

The value of the parameter to append.

Return value

None (undefined).

Examples

Adding the same parameter multiple times

js
const url = new URL("https://example.com?foo=1&bar=2");
const params = new URLSearchParams(url.search);

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

Specifications

Specification
URL
# dom-urlsearchparams-append

Browser compatibility

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
append

Legend

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Full support
Full support

See also