What is Lichess?
Lichess (short for “li[chess in sca]la”) is a free, open-source online chess game server that emphasizes realtime gameplay and ease of use. Built with no ads, tracking, or paywalls, Lichess serves millions of chess players worldwide. The platform runs entirely on donations and volunteer contributions, making professional-grade chess tools accessible to everyone.Key Features
Lichess provides a comprehensive suite of chess features:Play Chess
Real-time games with players worldwide, featuring bullet, blitz, rapid, classical, and correspondence time controls
Computer Analysis
Powered by Stockfish and distributed through the fishnet AI cluster using donated computing resources
Tournaments & Events
Organized tournaments, simultaneous exhibitions (simuls), and Swiss-system competitions
Training Tools
Tactics trainer, opening explorer, and lessons to improve your game
Studies & Analysis
Shared analysis boards for collaborative study and game review
Community Features
Teams, forums, and direct messaging to connect with other players
Additional Capabilities
- Search Engine: Browse and search through more than 4.7 billion games stored in MongoDB
- Mobile Apps: Native iOS and Android applications for chess on the go
- 140+ Languages: UI translations powered by the community through Crowdin
- Public Database: All rated games published as free PGN downloads
- HTTP API: Comprehensive REST API for integrating Lichess into your applications
Why Choose Lichess?
100% Free
No ads, no tracking, no paywalls. All features available to everyone.
Open Source
Licensed under GNU AGPL v3+. Transparent development on GitHub with active community contributions.
High Performance
Fully asynchronous architecture built for scalability with millions of concurrent players.
Privacy Focused
No personal data collection or advertising. Your privacy is respected.
Technology Stack
Lichess is built with modern, scalable technologies:- Backend: Scala 3 with Play Framework 2.8
- Frontend: TypeScript and snabbdom for reactive UI
- Database: MongoDB for game storage, Elasticsearch for search
- Caching: Redis for real-time communication and data caching
- WebSockets: Separate lila-ws server for handling real-time connections
- Chess Logic: scalachess library for pure chess rules and validation
- Styling: Sass for CSS generation
Lichess runs on a fully asynchronous architecture, making heavy use of Scala Futures and Akka streams to handle millions of requests efficiently.
Use Cases
For Players
Play casual or competitive chess games, train with puzzles, analyze your games, and join tournaments—all without spending a penny.For Developers
Use the Lichess API to:- Build chess applications and bots
- Access game databases and player statistics
- Integrate chess functionality into your projects
- Stream real-time game data
For Contributors
Join the open-source community to:- Add new features to the platform
- Fix bugs and improve performance
- Translate the interface into new languages
- Contribute to documentation
Get Started
Set up your local development environment and start contributing
Community & Support
Discord
Join the discussion
GitHub
View the source code
API Docs
Explore the API