Privacy

Last updated: 26 October 2026

Chess in 40 Seconds is a free chess-trap trainer. We keep data collection small: no accounts, no ads, nothing sold.

What stays on your device

Your progress (solved puzzles, daily goal), settings (theme, sound, voice) and your analytics choice are saved in your browser's local storage. They never leave your device. Clearing your browser data removes them.

Analytics

We use Mixpanel to see how people play: which puzzles and trap pages are opened, which puzzles are solved, when hints are used, which buttons are tapped, how long a visit lasts, which site or app sent you there, and technical errors. Events go through our own domain to Mixpanel and are stored in Mixpanel's EU data centre. We do not collect your name or email. Mixpanel uses your IP address only to work out an approximate location (country and city) and does not store the IP address itself. A random ID is kept in your browser's local storage so we can tell new and returning visitors apart.

Opting out: tap Opt out on the notice, or open the profile (top right) → Analytics settings → Opt out. After that nothing is sent from your browser. You can turn it back on the same way.

Links to other sites

Videos open on YouTube, TikTok or Instagram, and sharing opens the app you pick. Those services have their own privacy policies.

Your rights

If you are in the EU/UK you can ask us what analytics data relates to your device, or ask us to delete it. Because we don't know who you are, include the ID shown in your browser's local storage under mp_, or simply opt out and clear your browser data.

Contact

Questions: [email protected]