Node.js URLSearchParams.append()

Last Updated : 11 Jul, 2025

In URLSearchParams interface, the append() method adds a key/value pair specified by user. Syntax:

URLSearchParams.append(name, value)

Parameters: name - Input the parameter name to append value - Input the parameter value to append Example1:

javascript

let url = new URL('https://example.com/?par=1&par1=3');
let params = new URLSearchParams(url.search.slice(1));

//Add a second par parameter.
params.append('bar', 5);
console.log(url);

Output:

https://example.com/?par=1&par1=3&bar=5

Example2:

javascript

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

//Add a second par parameter.
params.append('bar', 2);
console.log(url);