Complete chess study software
1,917,619 master games, 70+ opening drills, local Stockfish, and deep visualization tools you will not find combined anywhere else, free to start.
Full-strength Stockfish analysis in your browser
Run Local Stockfish engine analysis in your browser on Chessyi. Eval bar, multi-PV lines, depth control, and best-move arrows, no install, instant feedback.
Spar with an adjustable engine opponent
Play chess against the computer on Chessyi. Adjustable strength from ~1200 to 2200+ ELO, choose your colour, set time controls, and practice real games in the browser.
Drill your openings with guided move validation
Train chess openings on Chessyi with 70+ named lines, move validation, hints, arrows, and repertoire-style practice. Build muscle memory for your opening repertoire.
Study master games from the largest built-in library
Browse 1.9 million chess games on Chessyi: 141 GM databases, 166 opening collections, famous classics, and repertoire lines. Load any game on the interactive analysis board.
Import, study, and export chess games as PGN
Paste or upload PGN files on Chessyi. Step through move history, analyse with Stockfish, export positions, and study your games on a full-featured interactive board.
See control, tension, and mobility as board heatmaps
Chessyi heatmaps overlay square control, mobility, tension, attacks, defense, and danger on the chess board. Understand positions visually, unique analysis no other free tool combines.
Attack arrows and defense markers per piece
Analyse individual piece activity on Chessyi. Toggle per-piece move arrows, attack and defense markers to see how each unit contributes to the position.
Material, structure, and king safety at a glance
Chessyi static analysis scores material balance, center control, mobility, pawn structure, king safety, development, and game phase, instant positional feedback without engine depth.
Dim the UI and study the board alone
Chessyi focus mode dims everything except the chess board for deep, distraction-free analysis and study sessions.
Make the board yours with 10 SVG piece sets
Customize Chessyi with 18 board backgrounds, 10 real SVG piece sets (solid and lined), and app colour themes. Merida, Cburnett, Staunty, pixel, and more.
Sync your study positions across devices
Save chess games and positions to your Chessyi cloud account. Pick up analysis on any device, secure sign-in with email verification.
Bullet, blitz, rapid, and custom clocks
Use Chessyi built-in chess clock for timed games vs the computer or local two-player. Presets for bullet, blitz, rapid, classical, plus custom controls.
Pass-and-play over-the-board practice
Play chess with a friend on one device with Chessyi local two-player mode. Full move validation, optional clock, and instant analysis after the game.
Replay legendary games every player should know
Study famous classical chess games on Chessyi. Load immortal games and legendary brilliancies on the analysis board with Stockfish and visual tools.
Build and drill your opening repertoire
Build your chess opening repertoire on Chessyi with repertoire PGNs, practice mode, and 166 opening game collections for real-world examples.
Your analysis stays on your device
Chessyi runs Stockfish locally in your browser. Your opening prep and analysis are not sent to a remote engine farm, privacy-first chess study.
Full analysis toolkit on phone and tablet
Chessyi works on mobile browsers with responsive layout, touch moves, and the full Stockfish engine. Study chess anywhere.
Ready to analyse like a master?
Open the board free, Stockfish, openings, and 1.9M games in one place.
Start for free