Privacy Policy

Ranked Sudoku ("we", "us") is operated by d-dev UG (haftungsbeschränkt), Rudolf-Schwarz-Str. 35, 10407 Berlin, Germany — see our Imprint for full company details. This policy explains what data we collect when you use Ranked Sudoku, why we collect it, and what rights you have over it. If you have questions, contact us at support@rankedsudoku.com.

Information we collect

Account & authentication data. We use Kinde as our authentication provider. When you sign up or log in, Kinde shares your email address and an authentication identifier with us. We do not receive or store your password — Kinde handles that directly.

Player profile & gameplay data.Once you complete onboarding, we store your self-reported skill level, a randomly assigned display name, your ELO rating, and your race/daily-game history. To power the ghost-run matchmaking system, we record the full interaction sequence of a completed puzzle — every digit you enter, every erasure, and the timestamp of each — as a "Ghost Run" that another player may later race against.

Technical data. Our hosting provider (Vercel) and infrastructure providers automatically log standard technical information such as IP address, browser type, and request timestamps, as part of running the service securely.

Cookies. We use a strictly necessary session cookie (set by Kinde) to keep you signed in. We do not currently use analytics or advertising cookies. If we introduce them in the future — for example, to show ads via Google AdSense — we will ask for your consent before any non-essential cookie is set, and you will be able to change your choice at any time.

How we use your data

We use the data described above to:

• create and maintain your account and player profile;
• run the core game: daily puzzles, races, matchmaking, and ELO calculation;
• show your display name and results on leaderboards;
• secure the service and prevent abuse; and
• where you've consented, personalize advertising and measure how the site is used.

Who we share data with

We share data with the infrastructure providers that run Ranked Sudoku, each acting as a processor on our behalf:

• Kinde — authentication and session management.
• Turso — our primary database, storing account, profile, and race metadata.
• Cloudflare (R2) — object storage for ghost-run replay data.
• Vercel — application hosting.

If we enable advertising (see below), Google will also process data on our behalf as an ad provider. We do not sell your personal data to anyone.

Advertising & Google AdSense

We may show ads on non-gameplay pages (such as this one or the technique guides) using Google AdSense, including its H5 Games Ads format. If enabled, Google and its advertising partners may use cookies or similar technology to serve ads and measure their performance, which can include using data to personalize the ads you see. This only happens after you've given consent where consent is legally required (including for all visitors in the EU/EEA and UK). No ads are shown inside an in-progress race.

You can view and manage the ad data Google holds about you at adssettings.google.com, and learn more about how Google uses data from sites that use its services at policies.google.com/technologies/partner-sites.

Data retention

We keep your account and gameplay data for as long as your account is active. If you want your account and associated data deleted, email us at support@rankedsudoku.com and we will process the request manually.

Your rights

If you're located in the EEA, UK, or another jurisdiction with similar data protection laws, you have the right to access, correct, delete, or export your personal data, to object to or restrict certain processing, and to withdraw consent at any time. To exercise any of these rights, email support@rankedsudoku.com. You also have the right to lodge a complaint with your local data protection authority.

Children's privacy

Ranked Sudoku is not directed at children under 16, and we do not knowingly collect personal data from them.

Changes to this policy

We may update this policy from time to time. We'll update the "Last updated" date above when we do.