Why does tea make you pee?

Tea doesn't make you urinate any more than any other drink containing water does.

Whether you drink a 200ml glass of water or a 200ml mug of tea, you'll urinate the same amount.

How much you urinate depends on how much you drink and how much of what you drink isn't absorbed by your bloodstream.

Some caffeinated drinks can cause contractions to the bladder giving you the feeling that you desperately need to urinate, when in fact you don't. Therefore coffee would make you feel the need to urinate more than tea.