Privacy Policy
Last checked: November 4, 2026
What this site keeps on your device
So your rating choice and practice progress are there next time, they are saved in this browser's storage (localStorage) only. Nothing is sent to a server. These are the three keys:
fm.band: the rating level you pickedfm.cards: for each practiced position, the next review date, the interval, right and wrong counts, and the moves that led therefm.lang: whether you closed the language suggestion
Clearing this site's data in your browser settings removes all of it. There are no accounts or logins.
What the site loads
Move statistics are read from files on this site (chess.lumenlab.page). The moves you play on the board are not sent anywhere. The font is loaded from jsDelivr.
Visit statistics
Cloudflare, which hosts the site, adds a small script for visit statistics (Cloudflare Web Analytics). It collects things like the page address, the previous page address, how long the page took to load and the browser type, and it does not use cookies. The moves you play and your practice progress are not part of it.
Advertising
This site may show Google AdSense ads. Third-party vendors, including Google, use cookies to serve ads based on your visits to this and other websites, and may collect information through web beacons. See How Google uses data when you use our partners' sites or apps; you can turn off personalized ads in Google Ad Settings. Visitors in the EEA, the UK and Switzerland see Google's consent message first.
Contact
Lumen Lab: contact@lumenlab.page