Account information
When you create an account, we collect your email address, password credentials in protected form, verification codes, sign-in/session information, and account status.
Privacy Policy
Effective date: June 21, 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.
Friendly note: This page is meant to be clear and practical. It is not legal advice. PM Technologies should have counsel review it before public launch.
Who runs Sudoku Skills
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 eric@pmtechllc.com.
Information we collect
We collect only the information we need to run, protect, and improve Sudoku Skills.
Puzzle activity
We store puzzle progress, saved puzzles, candidate notes, walkthrough history, nudges you reveal, lesson progress, badges, diploma progress, statistics, streaks, and related gameplay records.
Payment status
Full Access payments are handled by Stripe. We store subscription status, plan information, Stripe customer/subscription identifiers, and billing event records. We do not store full card numbers.
Technical information
Like most websites, we may process IP address, browser details, device details, pages requested, error logs, security/rate-limit logs, cookies, local storage, and service-worker cache data.
OCR and uploads
If you use scan import, Sudoku Skills may process the image you provide to read a puzzle grid. We use that image to support puzzle import and troubleshooting, not to identify you personally.
Messages from you
If you contact us, we may keep your message, contact details, and our response so we can help you and improve support.
How we use information
- To create and secure accounts.
- To save, resume, and replay puzzles.
- To provide nudges, walkthroughs, statistics, School progress, badges, and the Sudoku Skills Diploma.
- To provide Full Access features, billing status, Stripe Checkout, and Stripe Customer Portal access.
- To detect errors, prevent abuse, enforce rate limits, and protect the service.
- To respond to support requests and improve the product.
- To comply with legal, tax, accounting, security, and operational obligations.
How we share information
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.
Cookies, local storage, and offline support
Sudoku Skills uses cookies and similar technologies to 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.
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.
Your choices and privacy rights
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.
How long we keep information
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.
Security
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.
Children
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.
Changes to this policy
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.