Privacy Policy

Last Updated: July 2026

At solve-sudoku.io, we take your privacy seriously. This Privacy Policy explains how we handle information when you use our online Sudoku solving tool and optional account features.

Information We Collect

You can use the Sudoku Solver without creating an account. If you choose to create an account, we collect the information needed to provide account access and saved progress features:

• Your name and email address
• Your password, stored securely as a hash
• Authentication details from social login providers, if you use them
• Puzzle attempts, completion status, solving method, timing, error counts, and related statistics while you are signed in
• Messages you send to us by email, support requests, or feature request forms

Information We Don't Collect

We do not collect payment information, precise location data, or unnecessary device identifiers. Our service is free, and we do not sell your personal information.

How Our Solver Works

Most puzzle solving happens locally in your web browser using JavaScript. When you use the solver without signing in:

• All processing occurs on your device
• No puzzle data is sent to our servers
• No solving sessions are recorded or tracked
• Your progress is stored only in your browser's local memory during your session

When you are signed in, we may store puzzle attempt data so we can provide your personal statistics, puzzle history, and leaderboard features.

Browser Storage

We may use your browser's local storage or session storage to:

• Remember your dark mode preference
• Maintain your current puzzle during your session
• Save interface preferences (like pencil mode settings)

This data never leaves your device and can be cleared at any time through your browser settings.

Cookies

We use essential cookies to keep you signed in and protect your account session. We do not use cookies to sell your data or build advertising profiles.

Third-Party Services

We use Google Analytics for basic site performance monitoring. No personal data is collected or shared with Google.

Links to Other Websites

Our site may contain links to external resources for educational purposes. We are not responsible for the privacy practices of other websites. We encourage you to read the privacy policies of any external sites you visit.

Children's Privacy

Our service is appropriate for all ages. We do not knowingly collect personal information from children beyond what is needed to operate optional account features. Parents or guardians can contact us to request account deletion or changes.

Changes to This Policy

We may update this Privacy Policy from time to time to reflect changes in our practices or for legal reasons. When we make changes:

• We will update the "Last Updated" date at the top of this page
• Significant changes will be prominently announced on our website
• Your continued use of the service after changes constitutes acceptance of the updated policy

Your Rights

You may request access to, correction of, or deletion of your account information. Account deletion and account data changes must be requested by emailing support at admin@solve-sudoku.io.

• Clear your browser's local storage to remove any saved preferences
• Use private/incognito mode for completely anonymous sessions
• Email support to request account deletion or changes to account information
• Stop using the service at any time

Data Security

We use reasonable safeguards to protect account information and stored puzzle attempt data. Puzzle solving still primarily happens in your browser, and we recommend:

• Keeping your browser updated with the latest security patches
• Using reputable antivirus software
• Being cautious when using public or shared computers

Contact Us

If you have questions about this Privacy Policy, our privacy practices, or account deletion or change requests, please email admin@solve-sudoku.io or visit our Contact page.

Consent

By using our Sudoku Solver or creating an account, you consent to this Privacy Policy.