Privacy
Sudoku Showdown keeps as little about you as it can and still run a fair tournament. There are no ads and no analytics trackers, and nothing is sold or shared for marketing.
What we store
- An anonymous player ID
- Created automatically the first time you open the game, so your one submission per day and your result belong to you. It isn't linked to your name, email or device details.
- The name you choose
- Shown next to your time on the public leaderboard. If you don't pick one, you get a generated name like "Swift Otter 27". Offensive names are replaced with the generated one.
- Your daily result
- The board you submitted, whether it was correct, your time, your rank and how many numbers had been revealed. Your name, time, rank and reveals appear on the public leaderboard; your board does not.
- Play timing, for fair play
- With each submission we keep a few counts: how many digits you entered and erased, notes and undos, roughly when you entered digits, and how many times you opened the game that day. They're used only to spot solves that look automated, and a person reviews them. Nobody is banned automatically.
- That you played today
- A daily marker against your player ID, used only to count how many people played.
- If you sign in with Google
- Your Google account email and basic profile, held by Firebase Authentication so you can sign in on other devices. Your in-progress board is also saved to your account so you can pick up where you left off. Your email is never shown to other players.
On your device
Your browser keeps your sign-in and your in-progress board, so a reload doesn't lose your work. These are not tracking cookies; clearing your browser's site data removes them.
Who processes it
The game runs on Google Firebase and Google Cloud (United States), which store the data above and process your IP address to serve the site and keep it secure. To keep bots out, the site may use Google reCAPTCHA, which checks signals from your browser. Google's handling is covered by the Google Privacy Policy.
How long we keep it
Results and leaderboards are kept while the game runs, because past days and the all-time record are part of it. Daily visit markers are only used for counting.
Deleting your data
Email hello@sudoku-showdown.com and we'll delete your player record, name, results and any saved boards. If you signed in with Google, send it from that address. If you played anonymously, tell us your leaderboard name and a day you played so we can find you.
Children
Sudoku Showdown isn't directed at children under 13, and we don't knowingly collect their information.
Changes
If this changes, the date below will too.
Last updated October 21, 2026