Playground · Browser edition

Play Bongaclang.

My chess engine, running in your browser. It opens with the Bongcloud on purpose, then tries to win anyway.

Its stronger sibling plays 2,456 blitz on Lichess

Click or drag to move. The engine thinks on your device, in a Web Worker.

About this version

Two engines, one name.

The rating above belongs to the Rust engine that plays on Lichess. This board runs an earlier TypeScript port, small enough to think on your device.

Here, in your browser

TypeScript port

  • Alpha-beta search with a transposition table
  • Quiescence search, so captures settle before it judges
  • An opening book that walks the king out on move two
  • Runs entirely on your device, in a Web Worker

On Lichess, around the clock

Rust engine · 2,456 blitz

  • A neural evaluation network (NNUE) I trained
  • PVS, aspiration windows and selective pruning
  • New versions must win in self-play before they ship
  • Runs on a free Oracle Cloud VM
How it went from Python to Rust and a trained network→

Recent games

Watch the live engine.

Real games Bongaclang played on Lichess against people and other bots, straight from the public API.

Challenge it on Lichess
Loads content from lichess.org