Stockfish 19 is live
Since 20 September 2026, every position you analyse on ChessRank.org is evaluated by Stockfish 19, the newest release of the strongest chess engine in the world. The upgrade covers the whole site: Game Analysis, Move by move, the analysis board, Blunder Puzzles and the hints Coach Moji gives you while you play.
There is nothing to install and nothing to switch on. The engine ships with the app, it runs in your browser on your own device, and it stays free exactly as before.
What actually got better
A new Stockfish release comes down to two things: a smarter neural network for judging a position, and a search that spends its time on the lines that matter. Stockfish 19 improves both, and in practice you notice it in three places.
- Steadier evaluations. Quiet positions, where the advantage is hard to put a number on, are graded more consistently, so the evaluation bar swings around less.
- Better best moves. At the same depth the engine finds the critical continuation more often, so the best line in your report is worth more.
- Cleaner tactics. Long forcing sequences resolve earlier in the search, which means blunders and brilliant moves are caught with fewer false alarms.
Do my saved reports change?
No. Everything you have already analysed stays exactly as it was. If you run a game again, Stockfish 19 grades it from scratch, and on a handful of moves you may see a different badge than before. That is normal, and it is not a sign that either reading was wrong.
The model on top is still ours
Stockfish supplies the raw evaluation. The accuracy score and the badges on each move come from the ChessRank.org model that sits on top of it, and that model has not changed. A better engine means better evidence, the reading of that evidence is still our own.
Why we bother
An analysis is only as good as the engine behind it. There is no reason a free tool should hand you anything weaker than what the paid sites run, so we keep the engine current. It is the cheapest way to make every report on the site better at once.