Free Online Chess Analysis Tool - Stockfish Game Analyzer
Join the Chess It Up club on Chess.com →
PGN Input
Best Move
Top Moves
Accuracy
Summary
Free Chess Game Analysis
1. Load a game
Enter your Chess.com or Lichess username to pull your recent games, or paste a PGN from any site or over-the-board game.
2. Run the game review
Tap "Full Game Analysis". Stockfish runs in your browser and evaluates every position, at depth 12 on the free plan and up to depth 25 on Premium.
3. Read the grades
Every move gets a grade, from Brilliant to Blunder, plus your accuracy for the game. Tap any move to see the engine's best line on the board.
How Moves Are Graded
Grades come from win-percentage loss: how much your chance of winning dropped compared with the engine's best move.
- Brilliant: a sound sacrifice.
- Great Move: the only move that keeps the position; the next-best move loses at least 10% win chance.
- Best: the engine's top move.
- Excellent: under 3% win chance lost.
- Good: under 5% lost.
- Inaccuracy: under 9% lost.
- Mistake: under 22% lost.
- Blunder: 22% or more lost.
- Miss: your opponent made a mistake and you didn't punish it.
- Book: a known opening theory move.
Frequently Asked Questions
Is Chess It Up free?
Yes. Full game analysis with Stockfish is free with no daily limit. Premium adds deeper analysis (up to depth 25) and removes ads.
Do I need an account?
No. You can import a game and run a full review without signing up.
Can I analyze Chess.com and Lichess games?
Yes. Enter your Chess.com or Lichess username to load recent games, or paste a PGN from any platform.
How is accuracy calculated?
Each move scores by its grade: Best 96, Good 85, Inaccuracy 60, Mistake 35, Blunder 10. Your accuracy is the average across your moves.
What makes a move Brilliant?
A best or near-best move that sacrifices material, when you were not already completely winning. Winning trades and recaptures do not count.
Does it work on mobile?
Yes. The analyzer runs in your phone's browser.