How to Generate Random String in JavaScript

How to Generate Random String in JavaScript

Generating random string in JavaScript is extremely simple. Last day, I was working on a freelance project and I need to create a long random string using JavaScript. I used the following code snippet for that and you can use that code in your project too. Here goes the full source code.

– Function to Generate Random String:

function generate_random_string ( string_length ) {

    // If string length is not defined, by default we set it's value as 21
    if( typeof (string_length) == 'undefined') {

        string_length = 21;


    // Initialize random string
    var random_string = " ";

    var charset = "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    // Create a for loop
    for( var i=0; i < string_length; i++ ) {

        random_string += charset.charAt(Math.floor(Math.random() * charset.length));


    return random_string;


// Call The Function to generate a random string of 30 characters in length


Check Demo


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