Home›Privacy Policy

Privacy Policy

Last updated: 18 March 2026  |  Effective date: 18 March 2026

1. Introduction & Who We Are

Welcome to SudokuMaster.org ("we", "our", "us"). SudokuMaster.org is a free online Sudoku puzzle game operated as an independent website. Our contact email is sudokumaster.org@gmail.com.

This Privacy Policy explains what information we collect, how we use it, who we share it with, and your rights regarding your personal data. By using SudokuMaster.org you agree to the practices described in this policy. If you do not agree, please do not use our site.

We are committed to protecting your privacy. We do not require user accounts, we do not sell personal data, and we collect the minimum information necessary to provide a free, high-quality service.

2. Information We Collect

2.1 Information You Provide

SudokuMaster.org does not require you to create an account or provide any personal information to play. We do not collect your name, email address, phone number, or any form of personal identification as a condition of using the service.

If you contact us by email at sudokumaster.org@gmail.com, we will receive your email address and any information you choose to include in the message. We use this solely to respond to your inquiry.

2.2 Automatically Collected Information

If you accept analytics cookies, our third-party analytics provider (Google Analytics 4) automatically collects certain technical information including: your approximate geographic location (country/city level), browser type and version, operating system, device type (mobile/desktop), pages visited, time on page, referring URL, and screen resolution. This information is anonymised and does not identify you personally.

Your IP address is anonymised before collection. We have enabled IP anonymisation in our Google Analytics configuration.

2.3 Local Storage (Browser Data)

We store game data locally in your browser using the Web Storage API (localStorage). No data stored locally is ever transmitted to our servers. The following keys are stored:

  • sg_cookies — Your cookie consent choice (accepted/declined)
  • sg_theme — Your chosen colour theme
  • sg_sfx — Sound effects on/off preference
  • sg_music — Background music on/off preference
  • sg_track — Music track selection
  • sg_solved — Your total puzzles solved count
  • sg_streak — Your daily play streak
  • sg_lastPlay — Date of last puzzle played
  • sg_best — Your best solving times by grid/difficulty
  • sg_autocheck — Auto-check mistakes preference
  • sg_sfxvol — Sound effects volume level
  • sg_musicvol — Music volume level
  • sg_savedGame — Your in-progress puzzle (auto-expires after 24 hours)

You can delete all local data by clearing your browser's site data or localStorage at any time. This resets your game progress, streak, and preferences.

3. Cookies

We use cookies in two categories — Essential and Analytics. You are shown a cookie consent banner on your first visit and can change your preference at any time.

3.1 Essential Cookies

These are strictly necessary for the website to function and cannot be disabled. They do not identify you personally and expire when you close your browser or after a short session period.

3.2 Analytics Cookies (consent required)

We use Google Analytics 4 to understand how visitors use our site. Analytics cookies are only set after you click "Accept" on our cookie banner. You may decline and still use the full site with no restrictions. To opt out after accepting, visit our Cookie Policy page and click the opt-out link, or install the Google Analytics Opt-out Browser Add-on.

3.3 Advertising Cookies

SudokuMaster.org may display advertisements served by Google AdSense. Advertising cookies are only activated after you provide consent. Google may use these cookies to show you relevant ads based on your browsing activity. You can manage Google advertising preferences at adssettings.google.com.

4. How We Use Your Information

We use the information we collect for the following purposes:

  • Providing the service: Storing your game progress, preferences, and streak locally in your browser.
  • Analytics: Understanding which features are used, which pages are popular, and how to improve the service. Analytics data is aggregated and cannot identify individual users.
  • Advertising: Displaying relevant advertisements to generate revenue that funds the free service.
  • Support: Responding to emails sent to sudokumaster.org@gmail.com.
  • Legal compliance: Retaining records as required by applicable law.

We do not use your data for profiling, automated decision-making, direct marketing, or any purpose beyond those listed above.

5. Legal Basis for Processing (GDPR)

For users in the European Economic Area (EEA), UK, and similar jurisdictions, we process personal data on the following legal bases:

  • Consent (Article 6(1)(a) GDPR): Analytics and advertising cookies are processed only with your explicit consent, given through our cookie banner.
  • Legitimate interests (Article 6(1)(f) GDPR): We process anonymised technical data to maintain security, prevent abuse, and improve the service. We have assessed that this processing does not override your privacy rights.
  • Contractual necessity: Local storage data is necessary to provide the game features you have requested (saving your progress, preferences, and streak).

6. Third-Party Services

We use the following third-party services. Each has its own privacy policy:

  • Google Analytics 4: Web analytics. Data processed by Google LLC, USA. Google Privacy Policy. Consent required.
  • Google AdSense: Advertising. Data processed by Google LLC, USA. Consent required. Google Privacy Policy.
  • Google Fonts: Font delivery via fonts.googleapis.com. Your browser makes a request to Google servers when the page loads. Google Privacy Policy.
  • Hostinger: Web hosting. Your IP address may appear in server access logs retained by Hostinger for security purposes. Hostinger Privacy Policy.

7. Data Retention

Game progress stored in your browser (localStorage) persists until you clear your browser data. In-progress puzzle saves expire automatically after 24 hours.

Google Analytics data is retained for 14 months by default in our GA4 account.

Emails sent to us are retained for as long as necessary to resolve the inquiry and in accordance with applicable laws.

8. Your Rights

Depending on your location, you may have the following rights regarding your personal data:

  • Right of access: Request a copy of data we hold about you.
  • Right to rectification: Correct inaccurate personal data.
  • Right to erasure ("right to be forgotten"): Request deletion of your data. For local data, clear your browser storage. For analytics data, contact us.
  • Right to restrict processing: Ask us to limit how we use your data.
  • Right to data portability: Receive your data in a machine-readable format.
  • Right to object: Object to processing based on legitimate interests.
  • Right to withdraw consent: Withdraw analytics/advertising consent at any time without affecting the legality of previous processing. To withdraw, click "Decline" on the cookie banner or clear your browser cookies.

To exercise any of these rights, email us at sudokumaster.org@gmail.com. We will respond within 30 days.

9. California Residents (CCPA)

California residents have rights under the California Consumer Privacy Act (CCPA) including the right to know what personal information is collected, the right to delete, and the right to opt out of sale. We do not sell personal information. To exercise your rights, contact sudokumaster.org@gmail.com.

10. Children's Privacy

SudokuMaster.org is suitable for all ages and is particularly popular with children learning to solve puzzles. We do not knowingly collect personal information from children under the age of 13. If you believe a child under 13 has provided personal information to us, please contact us at sudokumaster.org@gmail.com and we will take steps to delete it.

SudokuMaster.org does not require any personal information to play — no name, email, or age verification is requested. The site is safe for children.

11. Security

We take reasonable technical and organisational measures to protect your data. Our site is served over HTTPS with TLS encryption. We do not store personal data on our servers — all game data is stored locally in your browser. Analytics data is processed by Google using industry-standard security.

No method of internet transmission is 100% secure. If you believe your data has been compromised, please contact us immediately.

12. International Transfers

Google Analytics and Google AdSense are provided by Google LLC, headquartered in the United States. Data may be transferred to and processed in the USA and other countries. Google relies on Standard Contractual Clauses (SCCs) approved by the European Commission for such transfers.

13. Changes to This Policy

We may update this Privacy Policy from time to time. Changes will be posted on this page with an updated "Last updated" date. Material changes will be flagged with a notice on the homepage for 30 days. Continued use of the site after changes constitutes acceptance of the updated policy.

14. Contact Us

For privacy-related questions, data requests, or concerns, contact us at:

SudokuMaster.org
Email: sudokumaster.org@gmail.com

We aim to respond to all privacy-related emails within 30 days.