Privacy note

Short version: your chess progress never leaves your device, and if you join the Pro waitlist we keep your email only to tell you when Pro launches.

Training data

Your puzzle rating, theme statistics, missed-puzzle queue, opening progress and last game are saved in your browser's localStorage. They are not sent to us. Clearing your browser data removes them.

Waitlist

When you join the waitlist we store: your email address, the date and time you signed up, which form you used, and a two-letter country code derived by our host (Cloudflare) from your connection. We do not store your IP address. The data lives in Cloudflare Workers KV.

We use it for one purpose: to email you about the Pro launch. We will not sell, rent or share it. Every email will include a way to unsubscribe, and you can ask for deletion at any time by replying to any message from us.

Analytics & cookies

No advertising trackers, no third-party analytics scripts and no cookies are set by this site. The chess engine runs locally in your browser.

Third parties

The site is hosted on Cloudflare Pages; Cloudflare processes requests as our hosting provider. Links to Lichess puzzle sources open lichess.org, which has its own privacy policy.

Last updated: October 2026.