Privacy

Updated October 31, 2026

No account needed. You can play everything without one, and then we don't know your name or email. If you make a secret-message or challenge link and type a name into it, that name becomes part of the link (after the # sign, which browsers never send to the server) and goes only where you share the link.

Local storage. Puzzle progress, streaks and preferences are stored in your browser's local storage. Unless you sign in, they are never sent to us.

If you sign in. Signing in with Google is optional. It lets you keep your progress on every device. When you sign in, Google tells us your name, email address and an account ID; we don't get your password or anything else from your Google account. We then store your game progress, streaks, stats and game settings with your account (on Cloudflare's servers, which host the site), plus a cookie that keeps you signed in. We use this only to sync your progress. We don't use it for ads, and we don't sell or share it. On the account page you can download everything we store or delete your account; deleting removes it from our database straight away. Signing out leaves your progress on the device you are using.

Analytics. We use Google Analytics to count visits and see which puzzles are played, and Cloudflare Web Analytics for page-load statistics (it sets no cookies). Google Analytics sets cookies. You can block both with any content blocker and the site works the same.

Advertising. The site does not show ads at the moment and loads no advertising code. If that changes, this page will say so, and name the cookies involved, before any ad appears.

Sudoku photos. When you scan a puzzle on the sudoku solver, the photo is shrunk on your device and sent through our server to an AI image-reading service (Volcano Engine Ark), which returns the digits it sees. We don't store the photo, and we use it for nothing else. To stop automated abuse, the page runs Cloudflare Turnstile, a check that usually needs nothing from you; we count scans per day by a one-way hash of your network address, never the address itself.

Feedback. If you send the feedback form, we store what you write, the page it is about, your browser's name and your country (from Cloudflare), and your email only if you give it, so we can fix the problem and reply. A photo is stored only if you tick the box to attach it, and is deleted after 90 days. Ask at the address below and we delete your message.

Children. The puzzles suit all ages, and a few holiday pages are marked "for kids" so a parent or teacher can play along. The site as a whole is not directed at children under 13, and we do not knowingly collect their data.

Your data. Clearing your browser's site data deletes everything we store on your device. If you signed in, the account page lets you download or delete what is stored with your account. For anything held by Google, use the links above.

Questions: hello@gridpuzzles.app