jQuery: reading the default PHP session cookie (and its token)

jQuery: reading the default PHP session cookie (and its token)

How to read the default PHP session cookie with jQuery.

A PHP session generated by the session_start() function automatically creates a random session cookie for the current session. We can actually access this cookie by getting the string contained within the document.cookie property. Using jQuery this task is pretty easy.

A PHP session starts just like this:

<?php session_start(); ?>

The session cookie is immediately accessible:

$(function() {

	console.log(document.cookie); // PHPSESSID=4b668f94a97ca6742adbf4ab74edd6ad 

We can get the token value pretty easily:

(function($) {
	$.getPHPSessionCookie = function() {

		var token = document.cookie.replace(/phpsessid=/gi, '');
		return token;



$(function() {

	console.log($.getPHPSessionCookie()); // 4b668f94a97ca6742adbf4ab74edd6ad 


This token could be easily used during AJAX requests as a further validation of session data, though all PHP developers use an additional encrypted token in the $_SESSION superglobal array to add an extra layer of protection. This means that this basic token should never be trusted.