Updated: October 6, 2026
This policy describes the current Sudoku website at sudokuonline.app.
Playing on the website
The website does not require an account or ask for your name, email address or payment details to play. Puzzles are generated and checked in your browser. The application does not send your puzzle moves or harbor progress to a game server.
We use Google Analytics 4 and Yandex Metrica to understand aggregate site use and improve the website. Google Analytics records standard page and navigation activity. Yandex Metrica also has click maps, link tracking, accurate bounce tracking and Webvisor enabled. These services can receive information about a visit, including pages and referrers, device and browser details, time of visit, browser identifiers, IP-derived location and interactions with site elements.
The analytics providers process this information under their own policies: Google Privacy Policy and Yandex Metrica terms. We do not use these services for advertising, and the website has no feedback form. Website requests also disclose connection information, such as an IP address, to the server delivering the site.
Cookies and local storage
The lang cookie remembers your language preference. Google Analytics and Yandex Metrica may set their own cookies or use browser storage and identifiers for analytics. Local storage keeps the timestamp when your next hint becomes available, shared between tabs on the same browser origin. Harbor restoration is in development: the public website does not read or save harbor victories. Local development builds also store completed-puzzle counts for testing restoration. There is no account or cross-device synchronization.
The current puzzle, its notes and undo history are held in memory and are lost on reload. Appearance settings are also session-only. If browser storage is blocked, the hint cooldown uses an in-memory fallback.
Your choices
Use your browser’s site-data controls for sudokuonline.app to remove the language cookie, analytics identifiers and local storage. Clearing site data resets your language preference and the stored hint timestamp, along with any harbor progress from local development builds. Stored values stay in your browser until they are replaced or you clear them. We cannot retrieve that local data for you.
Messages and privacy requests
If you contact us by email, we receive your email address, message and any attachments you choose to send. Send only information needed for your request. Correspondence is used to handle your request and necessary follow-up.
Depending on your location, you may have rights to access, correct or delete personal information you provide to us, or to complain to a data protection authority. Use the Contact page for privacy questions and requests.
Changes
When data practices change, this page and its update date will change too. Any further notice or consent required by applicable law will be handled separately.