decode URL query string

Job ID: 33573102

Budget: $10 – $30 USD

I need to decode the URL like this: https://xxx.xxx.com/WebAdministration/RegistForm.aspx?newx=ezPQn9j2ch%2BFsUUy2BsPQ60FHW6/YLAkhVIqbkblxgR6vAE1Ld55oVdQNhxrch9FJTQrzAf8b2x4r7oIXXStIg==
I need to know how is this query string encoded : ezPQn9j2ch%2BFsUUy2BsPQ60FHW6/YLAkhVIqbkblxgR6vAE1Ld55oVdQNhxrch9FJTQrzAf8b2x4r7oIXXStIg==
like base64, HEX or whatever that is, it should be turned into some readable parameters and values.