As of May 31, 2019, TetrisFriends.com has been shut down. The site had over a million registered users and was the most popular place to play Tetris online, particularly for multiplayer formats.
Tetris Friends was shut down as its parent company, Tetris Online, Inc. closed.
A member of the team posted the following quote on reddit:
Hello friends of the TetrisFriends.com
The end is near and we already know the date.May 31, 2019 will be the last day of TetrisFriends.We had a great time playing and had so many wonderful games. I personally have a really strong emotional bond to the game. I got to know one of my best friends in the TetrisFriends multiplayer. This game will always have a special place in my heart.
So what are Tetris fans to do? Here are some links you can still use to play Tetris online against other players:
The downside is these sites don’t boast nearly the same userbase or UI/UX that Tetris Friends did. One of the great things about Tetris Friends was its ranking system, such that you’d only play against players near your skill level.
Unfortunately until we get better alternatives, we’ll have to make do with what we have. Some people might be working on a reboot of Tetris Friends, so check back for updates.