Privacy Policy
Last updated: August 2026
What this app does
ChessDeeper has two parts. First, it's a reader for the public Chess.com and Lichess APIs: you type in a username, and the app fetches that player's public profile, stats and game history to display it back to you — no account needed for that. Second, it offers a free ChessDeeper account (email and password). You need one to run engine game reviews, because reviews are saved so your progress pages can be built from them.
Information sent to Chess.com
When you look up a username, that username is sent server-side to Chess.com's public Published-Data API to retrieve publicly available profile and game data. ChessDeeper does not send your IP address, browser details, or any other personal information to Chess.com beyond what a normal API request requires. See Chess.com's own Privacy Policy for how they handle that data on their end.
What's stored on our servers
If you don't create an account, nothing personal is stored — Chess.com and Lichess responses are cached briefly (a few minutes) to reduce repeat requests, and that cache isn't tied to you. If you do create an account, we store your email address and password (handled by our authentication provider, Supabase, which hashes the password — we never see it), plus the games you review and the per-move analysis of them, so your Progress and Fingerprint pages can be generated. You can request deletion of your account and its data at any time using the contact address below.
What's stored in your browser
Your preferences — board color, piece style, sound on/off, analysis depth — along with locally saved puzzles, pattern progress, streaks and training history, are stored in your browser's local storage. This data never leaves your device. Clearing your browser's site data removes it completely. Note that game reviews run while you're signed in are also saved to your account on our servers, as described above.
Cookies & analytics
ChessDeeper uses no tracking pixels and no third-party analytics. If you sign in, we set cookies that are strictly necessary to keep you logged in — these are set by our authentication provider (Supabase) and are not used to track you across other sites. If you never sign in, no cookies are set. If this ever changes, this policy will be updated before it happens.
Children's privacy
ChessDeeper is not directed at children under 13 and does not knowingly collect personal information from them.
Changes to this policy
If how we handle data changes, this page will be updated and the "last updated" date above will change accordingly.
Contact
Questions about this policy? Reach out at mjuhaishijaz.official@gmail.com.