- urldecode: documentation ( source)
<?php
echo urldecode('=%7B%221%22%3A%5B%22000000000000000%22%5D%2C%222%22%3A%5B%22000000000000000%22%5D%2C%223%22%3A%5B%22000000000000000%22%5D%2C%224%22%3A%5B%22111000000000000%22%2C%22000110000000000%22%5D%2C%225%22%3A%5B%22000000000000000%22%5D%2C%226%22%3A%5B%22000000000000000%22%5D%2C%2212%22%3A%5B%22000000000000000%22%5D%7D');