Lichess Puzzles: 5.7 Million Rated and Tagged Chess Positions

Lichess provides 5,751,400 chess puzzles extracted from 300 million analyzed games and verified by Stockfish NNUE engines. Updated monthly, the collection includes tactical tags and difficulty ratings for every position. The dataset was generated using over 50 years of CPU time to ensure engine-verified accuracy.

Use Cases

• Predicting puzzle difficulty ratings from board positions
• Categorizing tactical motifs using the provided tags
• Benchmarking chess engine performance on specific tactical themes

Strengths

• 5,751,400 unique puzzles
• Verified by Stockfish 12/13/14/15 NNUE at 40 meganodes
• CC0 1.0 public domain license

Limitations

• Positions are restricted to those occurring in Lichess online games
• Engine evaluation depth is capped at 40 meganodes per position

Provenance

Source

Lichess

Collection Method

Algorithmic extraction from 300 million games followed by engine re-analysis

Freshness

Updated monthly; current as of February 2026.

Geography

Global