Master the Grid
Effective date: September 6, 2026
We built Sudoku Skills to help people learn Sudoku with nudges, walkthroughs, saved progress, printable practice, OCR import, and a structured School. This policy explains what information we collect, why we use it, and the choices you have.
Sudoku Skills is operated by PM Technologies. In this policy, "Sudoku Skills," "we," "us," and "our" refer to PM Technologies and the Sudoku Skills service.
For privacy questions, contact us at support@sudokuskills.com.
We collect only the information we need to run, protect, and improve Sudoku Skills.
When you create or recover an account, we process your email address, password credentials in protected form, verification and password-reset code records, sign-in/session information, and account status. One-time codes are stored and compared in protected form rather than retained as readable production log data.
We store puzzle progress, saved puzzles, candidate notes, walkthrough history, nudges you reveal, lesson progress, badges, diploma progress, statistics, streaks, and related gameplay records.
Full Access payments are handled by Stripe. We store subscription status, plan information, Stripe customer/subscription identifiers, and a minimized billing-event inbox used to reconcile provider events. We do not store full card numbers or retain full Stripe event payloads in that inbox.
Like most websites, we may process IP address, browser details, device details, pages requested, error logs, security/rate-limit data, cookies, local storage, and service-worker cache data. Product and operational analytics minimize these identifiers and use one-way correlation hashes where a stable security or troubleshooting reference is useful.
If you use scan import, the original image is processed in your browser to recognize the Sudoku grid. The server receives derived cell and puzzle evidence for final OCR decisioning and validation, not the original photo. We use that derived evidence to support puzzle import and troubleshooting, not to identify you personally.
If you contact us, we may keep your message, contact details, and our response so we can help you and improve support.
We do not sell your personal information. We do not share your personal information with advertisers for cross-context behavioral advertising.
We may share information with service providers that help us operate Sudoku Skills, such as hosting providers, email delivery services, payment processors, security tools, analytics or logging tools, and professional advisors. These providers are expected to use the information only to provide services to us.
We may also disclose information if required by law, to protect rights and safety, to prevent fraud or abuse, or as part of a business transfer such as a merger, acquisition, or sale of assets.
Sudoku Skills uses cookies and similar technologies that are needed to run the app, keep you signed in, protect sessions, remember app state, support local recovery, and make the progressive web app work. The service worker may cache public app assets so the app loads faster and can recover more gracefully if your connection drops.
At launch, Sudoku Skills is designed not to use non-essential advertising cookies, retargeting pixels, or third-party behavioral analytics trackers. Because the current cookies and browser storage are used for core app, security, account, billing, and recovery functions, we do not show a separate cookie consent banner for those necessary technologies.
If we later add non-essential analytics, advertising, retargeting, heatmapping, or similar tracking tools, we will update this policy and add an appropriate consent choice before those non-essential tools are used where consent is required.
Private account data, API responses, generated PDFs, saved puzzle data, billing data, and solutions should remain protected by authentication and server-side controls. You can clear cookies, local storage, and browser caches through your browser settings, but doing so may sign you out or remove local recovery data.
You can contact us to request access, correction, deletion, or export of personal information associated with your account. Depending on where you live, you may also have rights to object, restrict certain processing, appeal a privacy decision, or opt out of certain uses. We will honor applicable privacy rights required by law.
You can cancel a Full Access subscription through the Stripe Customer Portal when available in your account. You can also ask us for help if you have trouble accessing your account or managing billing status.
We keep information for as long as needed to provide Sudoku Skills, maintain your account and progress, meet legal/accounting obligations, resolve disputes, prevent fraud or abuse, and operate secure backups. When information is no longer needed, we will delete it or de-identify it when reasonably practical.
We use reasonable technical and organizational safeguards designed to protect Sudoku Skills and the information we process. No online service can guarantee perfect security, so please use a strong password, keep your email account secure, and contact us if you believe your account has been compromised.
Sudoku Skills is not directed to children under 13. If you believe a child provided personal information without appropriate permission, contact us and we will take reasonable steps to address it.
We may update this Privacy Policy as Sudoku Skills grows. If changes are important, we will update the effective date and may provide additional notice in the app or by email when appropriate.