Chess Blunder Trainer
Review your blunders like daily puzzles.
How it works
Link your account
Enter your Chess.com or Lichess username. BlunderDrill pulls your recent games straight from the public API, with no password and no downloads.
Analyse your games
The Stockfish engine reviews every move you played and flags the exact moments you dropped a piece, missed a tactic, or walked into mate.
Review the blunders
Each blunder becomes an interactive position. Replay it, find the move you should have played, and burn the pattern in so it stops happening.
Filter by type and game phase
Not every mistake is worth the same drill. BlunderDrill lets you filter your blunders by type, such as hanging a piece, missing a tactic, or allowing checkmate, and by the phase of the game they happened in, whether opening, middlegame, or endgame.
Focus on the patterns that cost you the most, drill one weakness at a time, and skip the mistakes you already have covered.
Why drill your own blunders
Generic puzzle trainers show you positions from other people's games. They sharpen your tactics, but they never touch the specific mistakes that actually cost you rating points.
BlunderDrill is different. It trains you on the exact positions where you went wrong: the pinned knight you missed, the back-rank mate you allowed, the free pawn you gave away. Repeatedly facing your own patterns is the fastest way to stop repeating them, and it is why reviewing your games is the advice every coach gives first.
Works with Chess.com and Lichess
Connect any Chess.com or Lichess account and BlunderDrill reads your games straight from the official public APIs. No password is ever required to look up a player, and no game data is uploaded from your device. Everything comes from the sites you already play on.
Frequently asked questions
- Is BlunderDrill free?
- Yes. You can look up any public Chess.com or Lichess player and start drilling their blunders for free. Create an account only if you want to save your progress.
- Do I need to install anything?
- No. BlunderDrill runs entirely in your browser and can be installed as an app on your phone home screen if you want, but nothing is required.
- Which chess sites are supported?
- Chess.com and Lichess. BlunderDrill reads your games directly from their public APIs, so any rated or casual game you have played is available.
- How are blunders detected?
- The Stockfish engine evaluates each position before and after your move. When your move loses significant evaluation compared to the best available move, it is classified as a mistake or blunder.