Tetris Battle is a puzzle game on the social networking service website Facebook. It is a multiplayer Tetris game developed by Tetris Online, Inc. using Flash. In the game, Facebook users can play against friends in 2, 4, or 6-player modes, or play solo. The gameplay is slightly different for each mode. Tetris Battle became one of the most popular games among many players in 2011. In addition, the game ceased operation on May 31, 2019, due to the company's cessation of operations.