Free chess analysis
Chess analysis that does not stop at move 20
- Stockfish 19 runs in your browser
- Move grades, accuracy and key moments
- No account, no ads, no premium tier
Games are analysed locally. Nothing is uploaded unless you choose to share a report.
How it works
- 1
Choose a source
Chess.com or Lichess username, a game link, a pasted PGN or an uploaded file. Multi-game databases are split for you.
- 2
Pick a depth
Fast for blitz and bullet, Balanced for most games, Deep when the result mattered. Deeper means slower but more precise.
- 3
Review and explore
Step through the game, play alternatives on the board with the live engine, and export an annotated PGN.
What you get
Accuracy and centipawn loss
Both players scored on a transparent win-probability model, with per-phase breakdowns.
Every move graded
From brilliant to blunder, with the engine's preferred move whenever yours fell short.
Explore variations
Play any move on the board; the engine switches to live analysis of the new position.
Multiple engine lines
See up to five candidate moves with their evaluations, not just the first choice.
Share a report
One click creates a link your coach or opponent can open without an account.
Private by default
Analysis runs on your device. Reports stay in your browser unless you share them.
What good chess analysis looks like
A useful review answers three questions: where did the evaluation change, why did it change, and what should have been played. Chessblood puts the answers side by side. The evaluation graph shows every swing at a glance, the move list grades each move, and the engine panel shows the line you missed, in notation you can replay on the board.
The grades follow published thresholds, listed here, so you can trust that a “mistake” in one game means the same in the next. Book moves and forced moves are excluded from accuracy, because you deserve neither credit nor blame for them.
| Grade | Rule |
|---|---|
| ⧉Book | The position after the move appears in the ECO opening table (3,600 named positions). |
| →Forced | There was only one legal move. Forced moves are never praised or punished. |
| !!Brilliant | The engine's top move (or within half a point of it), and along the engine's continuation the mover is still at least two pawns' worth of material down after their own next reply. Ordinary trades never qualify. The position must not already be decided, and the mover must keep at least 35% winning chances. |
| !Great | The engine's top move in a position where the second-best move would have cost at least 10 percentage points of win probability: the only good move. Recaptures, captures of an equal or bigger piece and replies to check are excluded, because they are the natural move anyway. |
| ★Best | Matches the engine's first choice, or loses no more than half a percentage point of win probability. |
| ✓Excellent | Loses less than 2 percentage points of win probability. |
| ·Good | Loses less than 5 points. |
| ?!Inaccuracy | Loses between 5 and 10 points. |
| ?Mistake | Loses between 10 and 20 points. |
| ×Missed win | The mover had at least 85% winning chances and the move dropped them below 60% without falling below 30%. The win is gone but the game is not. |
| ??Blunder | Loses 20 points or more, or converts a winning position into a lost one. |
Frequently asked questions
What is the difference between game analysis and position analysis?
How deep does the engine search?
Can I analyse a position from a diagram or a book?
Does it identify the opening?
Is there a limit on how many games I can analyse?
Ready to see what the engine thinks?
Import a game from Chess.com or Lichess, or paste a PGN. The review takes under a minute and runs entirely in your browser.
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