Blunder

A position worth exploring? Take a photo. Blunder turns chessboard photos and screenshots into an interactive board, ready for analysis. From a screen, a book, or your photo library to your next move.

Download on the App Store

See Blunder in action

Blunder Library with folders, favorites and saved chess positions — Your chess library

An interactive chessboard with three Stockfish analysis lines — Explore the best moves

Blunder analysis in dark mode with the blue board theme — Five colors · Dark mode

Blunder analysis in dark mode with the brown board theme — Five colors · Dark mode

Features

From a photo to your next move

Scan in 1 second

Open the camera or choose a photo with a tap. Blunder finds the board, corrects its perspective, and recognizes the pieces. Use screenshots or photos of chessboards on screens and printed pages.

Stockfish support

Explore engine analysis powered by Lichess, with your choice of alternative lines. Tap a move to follow a variation, step back and forward, or return to the original position.

Build your library

Save favorites and organize positions into folders, from openings to endgames. Browse your recent games as miniature boards. Prefer to save only what matters? Turn off automatic history.

Color themes

Pick blue, brown, green, ic, or purple, and choose a piece style. Light and dark appearances follow your iPhone. Analysis lines can show piece icons instead of letters.

Share a position as FEN, or open it in Lichess or Chess.com. Keep your saved library in sync with iCloud.