See every move for what it really was.
Paste a game, or pull it straight from Chess.com or Lichess. Stockfish checks every position, labels each move from Brilliant to Blunder, and shows you the better one. Then play on the board to test your own ideas.
- Every move labelled
- Play any position yourself
- Retry your mistakes
- No sign-up
Review a game
1. e4 e5 2. Nf3
From pasted game to clear lessons in three steps
No account, no setup. Bring a game and MoveLens does the rest.
Bring a game
Paste its PGN, upload a file, or type your username under the Chess.com or Lichess tab and pick a recent game.
- Chess.com: open the game → Share → PGN → Copy.
- Lichess: open the game → the PGN tab under the board → Copy.
Choose your view
Enter your username and the board opens from your side. Or pick White or Black yourself. Then choose how deep Stockfish should look: Fast for a quick scan, Deep for a strong review, Maximum when you want the best possible answer.
Learn from it
Step through the game with the coach, read why a move was a mistake, then play your own moves on the board and get an instant verdict. Use Retry to find the better move yourself.
Built for understanding your games, not just scoring them
Eleven move labels
Brilliant, Great, Best, Excellent, Good, Book, Forced, Inaccuracy, Mistake, Miss and Blunder, shown right on the board.
A board you can play on
Drag or click any piece at any point in the game. Get the engine's verdict on your move straight away, and keep playing the line.
Retry your mistakes
On any mistake, press Retry. You get the position back and try to find a better move, with feedback on every attempt.
Coach and explanations
A plain-English comment for every move, the engine's preferred line, and the exact winning chances before and after.
Live engine lines
Switch on the top three engine lines for any position, including ones you create. Click a line to play it.
Accuracy and game phases
An accuracy score for each player, plus how you did in the opening, the middlegame and the endgame.
Key moments
Jump straight to the Brilliant moves, Mistakes and Blunders. Press ] and [ to move between them.
Evaluation bar and graph
See who is winning at every move. Click anywhere on the graph to jump there, and spot the turning point at a glance.
3,800 named openings
Know which opening you played and exactly when you left theory, with book moves marked.
Import by username
Find your latest Chess.com or Lichess games by username. No copy and paste needed.
Make it yours
Four scenery backgrounds, two plain themes, twelve boards and six piece sets. Draw arrows with a right-click, and turn on sounds.
Saved in your browser
Recent reviews open instantly next time. Copy or download an annotated PGN to keep or share.
What each label means
Every move is compared with the engine's best move. The difference is measured in winning chance, the percentage chance of winning from a position, because a lost pawn matters far more in an equal game than when you are already a queen up.
Don't just read the review. Test it.
The board is live. Stop at any move, play something different, and see straight away whether it was good.
- 1Move any pieceDrag it, or click it and then click the square. Legal squares are shown as dots. Pawns can promote to any piece.
- 2Get a verdictYour move is labelled like the rest of the game, with the evaluation, the best move and a short explanation.
- 3Keep goingPlay both sides, step back with the arrows, or click an engine line to follow it. Back to game returns you to the real moves.
- 4Retry a mistakeOn a mistake or blunder, press Retry. You are put back before the move and asked to find something better.
- 5Mark up the positionRight-click and drag to draw arrows; right-click a square to highlight it. Hold Shift for red or Alt for blue.
Qxb2 should lose the game. The best move was Rd1.
Make the board yours
Pick a scene, a board and a piece set. Your choice is remembered on this device.
Shortcuts
Frequently asked
Where do I find my game's PGN?
- Chess.com: open the finished game, press Share (the arrow icon), choose the PGN tab and copy it.
- Lichess: open the game, scroll below the board and copy from the PGN tab.
- Or skip all that: use the Chess.com or Lichess tab above, type your username and pick a game.
Is it free? Do I need an account?
MoveLens is free and needs no account or sign-up.
How long does a review take, and what do the depths mean?
The engine searches every position of your game. A deeper search finds better moves and takes longer, roughly in proportion to the number of moves. Times below are typical for a 40-move game on a fast computer; a shared free server can be slower.
| Depth | Search | Typical time | Best for |
|---|---|---|---|
| Fast | 12 ply, ≤0.15 s | ≈ 10 s | A quick scan |
| Standard | 16 ply, ≤0.4 s | ≈ 30 s | Everyday review |
| Deep | 20 ply, ≤1.5 s | ≈ 1–2 min | Learning from a game |
| Maximum | 24 ply, ≤3.5 s | ≈ 3–5 min | Important games |
Why does a label differ from another website?
No site publishes its exact rules for labels like Brilliant or Great, and engines differ slightly in how deep they look. MoveLens measures how much winning chance a move gives away compared with the best move, then applies the thresholds listed in the Move labels section. The idea is the same, the numbers are not identical.
How is accuracy calculated?
Each move gets a score from how much winning chance it lost against the best move. The game score blends a weighted average (sharp moments count more) with a harmonic mean (which punishes any very bad move). It is the same published formula Lichess uses.
Can I view the board from Black's side?
Yes. Choose Black under "View the board from", or type your username and leave it on Auto: MoveLens finds which side you played. You can flip the board at any time with the flip button or the F key.
Can I analyse a position from the middle of a game?
Yes. Step to the move you want and play on from there. The board judges every move you make, and the Engine tab shows the best lines for any position you reach.
Who can see my games?
Your game is sent to the server so the engine can analyse it, and the finished review is held in the server's memory for a limited time. The recent reviews on this page are stored only in your own browser, and you can remove them whenever you like.