Notice first
Pressure, defenders, tactical risks, and legal destinations become easier to scan.
A learning overlay for Chess.com
Turn every move into a learning moment.
See candidate moves, tactical risk, pressure, and opening ideas in the position where you are already studying. Feedback stays close to the board, so understanding can follow naturally.
Supports Chess.com onlyDesigned for analysis, puzzles, bots, lessons, and permitted practice.
Why it helps
Keep the move, evaluation, and line in one view.
Chess Overlay brings the move, its evaluation change, and the principal line together while the position is still fresh.
Compare before moving
Candidate squares are evaluated side by side, helping you build a repeatable thinking process.
Review the result
Use the post-move grade and principal line to review the move you chose.
Core features
Useful information, only when the board needs it.
Legal move clarity
Distinguish normal moves, captures, castling, promotion, and en passant without visual clutter.
Attack and defense counts
See how many pieces attack or defend a square, including practical battery and X-ray relationships.
Tactical risk
Spot hanging pieces, pins, forks, overloaded defenders, and hidden lines before they become losses.
Pre- and post-move evaluation
Compare legal destinations with grade markers before moving, then grade the completed move as Best, Excellent, Good, Inaccuracy, Mistake, or Blunder.
Openings and principal lines
View representative opening choices, pre-move PVs, and tactical lines as up to five numbered arrows on the board.
Windows native engine
Run the Stockfish 18 and Lc0 engines through the Windows Native Host.
Chess.com only
Works only on permitted learning pages.
Use it on analysis boards, puzzles, bots, lessons, and for personal practice. You are responsible for using it in rated games, tournaments, or games that prohibit outside assistance.
Get started
Three steps, then return to the board.
Install the Chrome extension and Windows engine, then open a Chess.com page.
View engine installation guide- 1
Install the extension
Add the official Chess Overlay extension from the Chrome Web Store.
- 2
Install the Windows engine
Download and fully extract the engine ZIP, then run install.bat.
- 3
Sign in and start learning
Sign in with Google, then open Analysis, a bot, a lesson or drill, or an unrated learning puzzle.
Frequently asked questions
Which chess sites are supported?+
Chess Overlay currently supports Chess.com only. Lichess is not supported.
Can it be detected on Chess.com?+
The extension is not detected. Using external tools during rated games may violate Chess.com’s Terms of Service. We recommend using it only for learning, analysis, puzzles, bots, lessons, and unrated casual games.
Does the extension play moves for me?+
No. It visualizes evaluation markers and principal lines; it never moves a piece or submits a move automatically.
Could I become dependent on it?+
Any aid can become a habit depending on how it is used. Choose candidate moves yourself first, enable only the feedback you need, and revisit the same position without the overlay afterward.
Learn from the position in front of you.
See evaluation markers and verified principal lines directly on the familiar board.