100% free · No account · No ads
A free chess analyzer, with nothing held back
Why it costs nothing
On many chess sites, game review runs on the site's own servers. Every review costs processor time, which is why full reviews are often rationed: a few for free, the rest behind a subscription.
Chessblood runs Stockfish 19 inside your browser, compiled to WebAssembly. When you review a game, your own device does the thinking. Our servers deliver the pages and the engine files, fetch your games from Chess.com or Lichess when you ask, and store a review only if you choose to share it. None of that gets more expensive when you analyse more, so there is nothing to ration and nothing to sell.
It also means your games stay with you. Positions are analysed on your device, and reviews are saved in your browser rather than in an account. See the privacy page for the details.
Three depths, all free
- 12FastDepth 12. A 40-move game in a few seconds. Good for blitz.
- 16BalancedDepth 16. About 15 seconds for a 40-move game. Our default.
- 20DeepDepth 20. About a minute for a 40-move game. For serious games.
What you get
Full game review
A grade for every move, accuracy for both players, an evaluation graph and the key moments, with the engine's better move each time.
Game reviewChess.com and Lichess import
Type a username, pick a recent game and the review starts. No copying and pasting PGN.
Import from Chess.comPGN analyzer
Paste a PGN or upload a file. Multi-game databases are split so you can choose the game you want.
Analyze a PGNBlunder checker
Jump straight to the moves that lost the game and see what you should have played.
Find blundersStockfish analysis board
Up to five engine lines with live depth, an evaluation bar and arrows, for any position you set up or paste.
Open the boardBoard editor and FEN tools
Build a position from scratch, check it is legal and ask the engine for the best move.
Edit a positionAccuracy calculator
Accuracy and average centipawn loss for both sides, with the formula written out in full.
Calculate accuracyElo and rating calculators
Rating change for one game with any K-factor, or a whole tournament with your performance rating.
Calculate ratingOpening guides and trainer
Eight major openings with validated lines, plans and traps, and a trainer to drill them move by move.
Study openingsCheckmate puzzles
Mate-in-one to mate-in-three puzzles, each proved by a solver to have a forced mate.
Solve puzzlesCoach insights
After a few reviews, see which phase of the game costs you the most and which opening to study.
Meet the coachShare and export
Create a public link to any review, or download an annotated PGN with evaluations that opens in any chess program.
See a review
What free does not include
Accounts and cloud sync
Reviews are kept in the browser you used, up to the twelve most recent. Use Share or the PGN download to keep a copy elsewhere.
A server-side engine
The engine runs on your device, so a phone takes longer than a laptop. The Fast preset keeps reviews quick on slower hardware.
Endgame tablebases
Endings are judged by search, not looked up, so a won ending may show as a large plus score rather than a mate in 40.
Master databases and video lessons
There is no database of grandmaster games, no opening statistics and no human coaching. Paid services earn their fee here.
Free chess analyzer questions
Is it really free? What is the catch?
How can unlimited analysis be free?
Do I need an account to save my reviews?
Does it work on a phone or tablet?
How does it compare with paid analysis tools?
Analyze your last game now
Type your Chess.com or Lichess username, or paste a PGN. The review runs in your browser and takes about a minute or less.
100% free · No account · No ads