Coco Chess Engine
A little wonder.
A deeper game.
Coco is a free, open-source C++20 chess engine with NNUE evaluation. Play against it or analyse positions through the Universal Chess Interface (UCI).
Windows, Linux & macOS GPL-3.0
Requires a UCI-compatible chess GUI. Setup guide
What goes into
a move.
Coco combines a neural evaluation of the board with a search through possible continuations.
- Neural evaluation
- A 512-unit NNUE evaluates positions and updates as pieces move. It is embedded in every release, so no separate network download is needed.
- Parallel search
- Lazy SMP lets multiple workers explore the game tree while sharing search results. Move ordering helps Coco examine promising continuations first.
- Analysis & endgames
- MultiPV lets your chess GUI display several candidate lines. With optional Syzygy tablebases, Coco can probe supported endgame positions.
Inside version 1.5.
Coco 1.5.0 improves search, board-state handling, time allocation, and compatibility while retaining the existing 512-unit NNUE. The release notes document the changes and testing conditions.
Coco 1.5.0 release notesA little about Coco.
Coco Chess Engine is an open-source C++20 UCI engine maintained by NotKaede-11. Its source is available to study, build, and contribute to under the GPL-3.0 license.
Named after Coco from Witch Hat Atelier, and built with the same spirit of curiosity. Coco Chess Engine and CuckooChess are different projects.