Privacy Policy

This site is built to be friendly: no login, no personal accounts, no email collection. Here's exactly what happens when you play.

What's stored on YOUR device

Your puzzle progress, completion times, streak, and personal-best scores are saved in your browser's LocalStorage. This data never leaves your device. Clearing your browser data removes it.

Optional public scoreboard

When you finish a puzzle, you can opt in to add your time to the public leaderboard. If you opt in, you choose a display name (3–16 characters). We save: your chosen name, the puzzle ID, your time, and your mistake/hint counts. We do not save your IP, email, location, or any other identifying data. You can leave the leaderboard at any time by emailing us — we'll remove the entry.

Analytics

We use privacy-respecting analytics to count visits and understand which puzzles are popular. No personally identifiable information is collected. No tracking pixels, no third-party advertising cookies.

Cookies

We don't use cookies. LocalStorage handles all in-browser persistence.

Your rights

Under GDPR / CCPA, you have the right to know what personal data we hold and to request its deletion. Since we collect essentially none — only your opt-in display name on the leaderboard — there's not much to request, but contact us at hi@killersudoku.us if you'd like a leaderboard entry removed.

Changes

We'll update this page if anything changes. The date at the top reflects the last revision.