Lichess

Lichess is a completely free, open-source chess server founded by Thibault Duplessis in 2010 as a weekend project. It has since grown into one of the largest chess platforms in the world, with over 9 million monthly active users and more than 10 billion games played. Unlike commercial alternatives, Lichess has no ads, no paywalls, no premium tiers, and no user tracking — every feature is available to everyone for free.

The platform is powered by volunteers and donations. Thousands of contributors share computing power through the Fishnet network, providing unlimited Stockfish analysis to every user — a feature that costs money on competing platforms. The entire codebase is open-source under the AGPL license, with over 400 GitHub contributors building and improving the platform.

Lichess offers a comprehensive feature set that rivals any paid chess platform: real-time games across all time controls, a massive puzzle database (including Puzzle Storm, Puzzle Streak, and Puzzle Racer), an opening explorer backed by millions of master games, collaborative Studies for sharing annotated games, Arena and Swiss tournament hosting, and simultaneous exhibitions. The platform supports 140+ languages and has full-featured mobile apps for iOS and Android.

For chess coaches, content creators, and club organizers, Lichess provides a public API, embeddable boards, and tournament tools — all completely free. It is the gold standard for what a community-driven chess platform can achieve.