Chessmark

ChessMark Privacy Policy

Effective date: May 28, 2026

ChessMark is a local-first Chrome extension for bookmarking chess positions from Chess.com and Lichess for later study. It does not include a backend service, user accounts, analytics, advertising, or remote uploads.

Information ChessMark Handles

When you use ChessMark to save a position, the extension may store the following information locally in your browser:

• A cropped screenshot of the visible chess board.
• The board position in FEN when it can be captured or reconstructed.
• Notes and tags that you enter.
• The source site, source URL, page title, timestamp, and extension version.
• Player names, game IDs, game time controls, player ratings, or similar page metadata when they are visible and detected on the supported chess site.

ChessMark only runs on the supported chess sites declared in its extension manifest. It does not read cookies, passwords, payment information, authentication tokens, or browser history.

How Information Is Used

ChessMark uses this information only to provide its single purpose: saving and managing a private local library of chess positions that you choose to bookmark.

Saved information is used to show your ChessMark library, search and filter saved positions, filter by saved date or visible rating metadata, copy FEN, export saved data, and open saved positions on Chess.com or Lichess analysis boards.

Storage, Sharing, and Transfers

ChessMark stores saved positions in Chrome’s extension storage on your device. ChessMark does not transmit your saved positions, screenshots, notes, tags, URLs, or metadata to the developer, third-party analytics services, advertising services, or data brokers.

ChessMark does not sell, rent, share, or use your information for advertising or credit-worthiness decisions.

If you choose to open an analysis link, Chrome will navigate to Chess.com or Lichess with the FEN position in the URL so that site can display the board. Those sites handle their own pages under their own privacy policies.

Your Controls

You can delete individual bookmarks, clear all saved bookmarks, and export your saved data as JSON or FEN text from the ChessMark library page.

Removing the extension from Chrome also removes the extension’s local storage from that browser profile.

Chrome Web Store Limited Use

ChessMark’s use of information received from Chrome extension APIs complies with the Chrome Web Store User Data Policy, including the Limited Use requirements. ChessMark uses handled data only to provide or improve its single user-facing purpose and does not transfer handled user data except as described in this policy.

Contact

For privacy questions, use the support contact listed on the Chrome Web Store listing or the project’s GitHub repository.