Small, portable and suitably unique random ID functions for typical web application use

browser_id.js

function uniqueId() {
    var a = new Uint8Array(12);
    crypto.getRandomValues(a);
    return btoa([].slice.call(a).map(function(c) {
        return String.fromCharCode(c);
    }).join('')).replace(/[/+=]/g, '');
}

node_id.js

const crypto = require('crypto');

function uniqueId() {
    return crypto.randomBytes(12).toString('base64').replace(/[/+=]/g, '');
}

php_id.php

<?php

function uniqueId()
{
    $bytes = function_exists('random_bytes') ? random_bytes(12) : openssl_random_pseudo_bytes(12);
    return preg_replace('~[/+=]~', '', base64_encode($bytes));
}

UniqueId.md

Each of the functions in this Gist use a system provided source of cryptographically secure random bytes. Typical, built-in random number functions are weak and unreliable for true randomness. These functions are small, dependency-free and fairly portable across different language versions and environments. They have each been tested repeatedly over many millions of iterations.