Privacy policy

Last updated: 1 October 2026

This policy explains what Sudoku Knockout (the game at sudokuknockout.com and in the iPhone and Android apps) stores about you, why, and what you can do about it. In short: the game keeps only what it needs to run. There is no advertising and no tracking.

Questions or requests about your data: [email protected]

Who is responsible

Sudoku Knockout is published by Baran Doğan, who is responsible for your personal data (the “controller”). You can reach us at [email protected].

What we store

Your account. A random account ID, created the first time you open the game (you start as a guest). Your display name, avatar color and friend code. If you save your progress or sign in: your email address, and the language of the emails we send you.

Your games. Your solo and online results and statistics: games played, wins, times and daily challenges. The puzzles you start and finish, with your time and the second each cell was filled in (not the digits), which power friends’ leaderboards, ghost races and how many players finish each puzzle. For online games: the rooms you were in, your moves, power-ups and results.

Friends. Your friends, friend requests, room invites and challenges.

Notifications. If you allow notifications on your phone: a notification token for your device, and your app language so notifications reach you in it.

Feedback. What you write in the feedback form, with the app version, device model, system version and language. It is emailed to us, together with your email address if your account has one, so we can reply.

Technical data. When you use the game, our service providers record technical data such as your IP address and device type in their logs, to keep the service secure and running.

On your device. The game keeps your settings, statistics and the game in progress in your device’s storage, so it works offline and starts where you left off.

What we don’t do

We don’t show ads, track you across other apps or websites, or sell or share your data for marketing. The game contains no advertising or third-party analytics tools.

What other players see

Your display name and avatar color, and your friend code if you share it. In a game, your progress and result; in Race, Blitz and Knockout nobody sees your digits. Friends also see your daily challenge times, your record against them and how your challenges went.

Why we use your data

• To provide the game you asked for: your account, games, friends and notifications.
• To keep the game secure and fair, to fix problems and, added up across all players and never about you alone, to see how the game is used and make it better.
• Notifications only with your permission, which you can withdraw in your phone’s settings at any time.

For players in the EU, the UK and Turkey, the legal bases are, in the same order: performing our agreement with you, our legitimate interests, and your consent.

Who processes it for us

• Supabase: the database, sign-in and server functions.
• Cloudflare: hosting this website, and our email address.
• Resend: sending emails with sign-in codes, and passing feedback on to us.
• Expo: delivering notifications to Apple’s and Google’s notification services.
• Apple and Google: the app stores and notifications on your phone.

Some of them process data outside your country, including in the United States. They are bound by contracts that protect it, such as the EU Standard Contractual Clauses.

How long we keep it

• A guest that isn’t played for 90 days is deleted, with everything in it.
• An account with an email is kept until you delete it.
• When a guest signs in to an account, you choose: add its games to the account, keep it separate, or (if it has nothing in it) it is deleted.
• Feedback is kept for as long as we need it to deal with it. If you delete your account, it stays without a link to you.
• Our providers keep their logs for their usual short periods.

Your choices and rights

• Change your name at any time on the Me tab.
• Delete all your data and keep the account, or delete the account itself: Me → Your account → Your data. Deleting is immediate and can’t be undone.
• Turn notifications off in your phone’s settings.

You also have the right to see the data we hold about you, correct it, get a copy, object to how we use it, and complain to your data protection authority. Write to [email protected].

Children

The game is for a general audience and isn’t directed at children under 13. If you think a child has given us personal data, write to [email protected] and we’ll delete it.

Changes

If this policy changes, the date at the top changes too, and if the change matters we’ll tell you in the game.