Tenhou is one of the best sites out there for playing Riichi Mahjong online. You can join games for your skill level, or create lobbies where you can play with your friends. And the best part: its all free!

Tenhou, however, happens to be a Japanese site and there is no English option. But that is no problem. You can find the directions on using the site any other documentation you’re looking for on Tenhou right here.