lichess.org

Play chess with a friend, with a random player or with the computer. It is free. You don't have to register. There are no ads. Lichess lets you focus on the game by removing all clutter. Two-player games between humans Single-player (versus the artificial intelligence, Crafty) Time controls for chess clocks, including Fischer time settings User-defined restriction of who can join games, based on player rating Chess960, also known as Fischer Random, chess variant Premoves moretime() Castling, en passant, and pawn promotion and under-promotion Detection of check, checkmate, and stalemate Threefold repetition draw recording (must be claimed by player) Integrated chat Visual move validation while choosing destination squares Game replay and analysis Spectator mode Per-game export in portable game notation Database export of information about all games played by a given person as comma-separated values (CSV) Translated to fifty languages Works in any Internet browser (except IE6/IE7), with no Flash and no plugins.