# Lichess

♞ lichess.org: the forever free, adless and open source chess server ♞

Repository: https://github.com/lichess-org/lila
Canonical: https://ross.abutalabs.com/products/lichess
Homepage: https://lichess.org
Language: Scala
License: AGPL-3.0
License Family: copyleft
Topics: scala, chess, play-framework, non-profit, functional-programming, type-safe, typescript, free-software, game, lichess
Last push: 2026-08-26T04:18:33+00:00
Link (homepage): https://lichess.org
Link (site_page): https://lichess.org/faq
Link (site_page): https://lichess.org/features
Link (site_page): https://lichess.org/about

## Health v2 (maintenance only)
Score: 67/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 8, longevity 100
- inputs: {"age_days": 5307, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 18677, forks 2774 (observed 2026-08-28T04:11:27.016384+00:00)

## What it is
Lichess (lila) is a free, adless, open-source online chess server written in Scala 3 on a modified Play framework, with a TypeScript web client and mobile apps. It supports realtime play, tournaments, puzzles, Stockfish computer analysis, studies, and a free PGN game database.

## Use cases
- play chess online for free without ads
- run or join arena and swiss tournaments
- solve chess tactics puzzles
- analyze my games with Stockfish
- study openings with a large game database
- self-host an open-source chess server
- play correspondence chess
- share and collaborate on chess studies

## When to choose
- you want a fully free, ad-free, open-source chess platform
- you need realtime multiplayer chess with variants and tournaments
- you want engine analysis, puzzles, and training tools in one place
- you want to build on or fork an open-source chess server or its API/database

## When to avoid
- you need a small embeddable chess library rather than a full server (use chessground or scalachess)
- you require commercial support or SLAs
- you want a lightweight offline chess app without server infrastructure

## Facets
- artifact type: application
- maturity: stable
- function: web-framework, http-server, websocket, search-engine, machine-learning, api-framework, templating, routing
- domain: gaming-tools, web-development, education, analytics
- platform: cross-platform, browser, self-hosted
- tags: chess, scala, play-framework, stockfish, non-profit, open-source, tournaments, puzzles, mongodb, elasticsearch, redis, typescript, mobile-app, pgn-database, real-time, web-server, mobile, docker, linux

## Member repositories
- lichess-org/lila (main) score 67
- lichess-org/mobile (frontend) score 99
- lichess-org/lichobile (mirror) score 10
- lichess-org/chessground (frontend) score 87

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:27.016384+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:01:20.279288+00:00, confidence not recorded.
  - readme: https://github.com/lichess-org/lila (fetched 2026-08-28T04:11:27.016384+00:00, sha f22b7063572f)
  - homepage: https://lichess.org (fetched 2026-08-29T08:00:16.793655+00:00, sha d14349e1ff5b)
  - site_page: https://lichess.org/features (fetched 2026-08-29T08:00:16.849487+00:00, sha a76f209356ff)
  - site_page: https://lichess.org/about (fetched 2026-08-29T08:00:16.861782+00:00, sha cfe6dc02a23a)
  - site_page: https://lichess.org/faq (fetched 2026-08-29T08:00:16.846660+00:00, sha 42c8c6bcf187)
- Data as of 2026-08-30T08:39:29.467469+00:00.