Lichess
The world's largest open-source chess platform. No ads, no premium paywalls, no accounts required for casual play. Just chess.
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Play Lichess →Opens in a new tab on the original host.
Controls: Click and drag pieces. Keyboard shortcuts available in settings.
Lichess is a chess server that runs entirely on donations and open-source software. There are no ads. There is no subscription tier for core features. The strongest analysis engine (Stockfish) is free to everyone. The puzzle trainer is free. The opening explorer is free. The entire server software is on GitHub.
Thibault Duplessis started it in 2010 as a side project, and it has grown into the largest chess server on the internet by games played — consistently handling more games per day than any other platform. The site processes millions of games annually, runs Stockfish 15+ analysis on demand, and has never had a round of funding.
For casual players, Lichess offers rapid and blitz games against strangers with zero account setup. For serious players, the opening explorer, game analysis, and ranked ladder are all world-class. For learners, the puzzle trainer is arguably better than anything available commercially.
Why it’s on the guide: AGPL-3.0 throughout the stack, one of the most successful open-source projects on the web, and genuinely the best product in its category — not despite being free but partly because of it.