Privacy Policy

Privacy by design

Your analysis runs in your browser. We don't upload your games to our servers.

Last updated: February 11, 2026

The short version

Chessomy runs in your browser. Your analysis stays on-device unless you export it. We don't collect or sell personal information, and you can delete local data anytime. We use anonymous analytics to improve the site and fetch your public games from Chess.com or Lichess when you ask us to.

What we don't collect

No game uploads
Your chess games are analyzed locally and not uploaded to our servers.
No credentials
We never ask for passwords. We only use your public username.
No tracking cookies
No advertising, tracking, or marketing cookies.
No personal information
No names, emails, or identifying information collected.
No behavioral tracking
No behavior tracking, profiling, or data selling.

What stays on your device

Analysis cache

Parsed games, engine evaluations, and accuracy summaries live only in your browser storage.

Profiles & preferences

Preferred usernames, analysis presets, and study mode settings are stored locally.

Cached assets

The app shell and Stockfish engine are cached after your first visit for offline access.

You control it

Clear your browser storage at any time to remove all Chessomy data.

Third-party services

Chess.com & Lichess APIs

When you enter a username, we send it to the Chess.com or Lichess public API to fetch your games. Only your public username is shared — no other data leaves your browser.

Vercel Analytics

We use Vercel Analytics to collect anonymous, aggregated page-view and interaction data. No personal identifiers or cookies are involved.

Vercel Speed Insights

We collect anonymous performance metrics (page load times, web vitals) through Vercel Speed Insights to keep the site fast.

Rate limiting

Your IP address is briefly held in server memory to enforce API rate limits and prevent abuse. It is not persisted, logged, or used for tracking.

Questions about privacy?

Reach out if you want clarifications or to request data removal guidance.