This notice explains what information is processed when you use sudokunaut.de, why it is needed and how to manage optional services.
1. Controller and contact details
Timon StronczekPosener Weg 353119 Bonn, DeutschlandPhone: +49 1575 2672544E-Mail: info@electi-venture.deThe contact address above can also be used for privacy-related requests.
2. What information is processed
Sudokunaut does not require an account. Your puzzles, entries, notes, completed games, scores, streaks and preferences are stored on your device. We do not maintain a central database of your game progress.
Separate from this, technical connection data is processed when the website is delivered. With appropriate consent, Matomo statistics and Google advertising can be used.
3. Hosting, access logs and security
We host sudokunaut.de on our own server infrastructure. Website requests may involve your IP address, the time and requested resource, HTTP status, transmitted data volume, browser information and referrer data. This is necessary for delivery, troubleshooting and protection against attacks.
Legal basis: Article 6(1)(f) GDPR (legitimate interest in a secure and operational service). Section 25(2)(2) TDDDG applies to technically essential device access where applicable.
Retention: We retain access logs for as long as they are necessary for the security and operation of our website, particularly to investigate technical problems and prevent misuse. They are deleted when these purposes no longer apply, unless legal obligations require longer retention.
Fonts, game graphics and other core application resources are delivered from our site; no external fonts or map services are needed.
4. Sudoku progress and local storage
Your game progress, notes, scores, achievements, preferences and completed games are primarily stored in your browser’s IndexedDB. Small UI preferences and practice sequence counters are stored in Local Storage. This allows the requested save-and-resume functionality without an account.
To the extent that local storage is technically necessary for these explicitly requested functions, Section 25(2)(2) TDDDG applies. Where personal data is involved, Article 6(1)(b) or (f) GDPR may apply according to the purpose.
The information stays on the device until you delete it in the application or the browser removes its site data. We cannot recover or remotely erase your local game data. The export/import feature transfers data only through the JSON file you handle yourself; there is no cloud synchronization.
5. Consent and privacy settings
We use Google Privacy & Messaging and its IAB Transparency and Consent Framework (TCF) message to manage optional data processing. Both our Matomo analytics and Google advertising are governed by this one consent manager. There is no additional Matomo consent toggle.
Where consent is required, the legal basis is Article 6(1)(a) GDPR and Section 25(1) TDDDG. Technical processing for documenting the consent decision may rely on Article 6(1)(c) or (f) GDPR as applicable.
To display the Google consent interface, a Google script is loaded before you make your decision; this creates a technical connection to Google, potentially including your IP address. This must be distinguished from consent to analytics or personalized advertising.
You can change or withdraw your choice at any time using the following button or the cookie settings in the footer. This opens the same Google dialog. Withdrawing consent prevents future optional processing but does not automatically erase data lawfully processed earlier.
6. Usage analytics with Matomo
With your explicit consent granted through Google Privacy & Messaging, we use the self-hosted analytics software Matomo to measure page views. Its tracking script is not loaded until the necessary consent has been confirmed. Tracking cookies are disabled, and Do Not Track / Global Privacy Control preferences are respected.
Depending on the technical environment, the tracker may process timestamps, page paths, browser and device characteristics and the IP address used for the connection. We do not send the numbers you enter, notes, puzzle solutions or your stored game history as Matomo events. URL query parameters and fragments are excluded from tracking.
We operate Matomo on our own infrastructure and use it without tracking cookies. IP addresses may be processed during the technical connection; analytics data is evaluated separately from your locally stored Sudoku progress.
Legal basis: Article 6(1)(a) GDPR and, where applicable, Section 25(1) TDDDG.
We retain personal analytics data only for as long as it is needed to evaluate website usage and improve the service. When this purpose no longer applies, the data is deleted or anonymized. Aggregated statistics that no longer identify individuals may be retained for longer.
7. Advertising with Google AdSense
To finance our free service, we may use Google AdSense Auto ads. Depending on the consent decision, Google and participating advertising partners may process IP addresses, page URLs, browser and device attributes, advertising interactions and cookies or similar identifiers. Personalized advertising may also be shown if you agree to the relevant purposes.
Locally stored Sudoku boards, notes and scores are not deliberately transferred to Google as advertising parameters. Advertising requests remain paused until the Google consent manager reports the relevant authorization. The CMP itself requires a technical connection to Google.
Legal basis: Article 6(1)(a) GDPR and Section 25(1) TDDDG, insofar as consent is required. Purposes and recipients are described in the Google consent dialog.
8. Recipients and international transfers
The site and Matomo are hosted on our infrastructure. Network and data-centre providers may have access to connection data where technically necessary. Google and the partners shown in the consent manager can process data depending on the purposes authorized.
Personal data may be transferred outside the European Economic Area, including to the United States. Depending on the recipient and circumstances, an adequacy decision (such as the EU–US Data Privacy Framework for certified organizations) or other appropriate safeguards may apply.
9. Contact by email
If you email us, we process your address and message to respond to your request. Depending on the nature of the request, the legal basis is Article 6(1)(b) or (f) GDPR. Messages are deleted when no longer needed, unless retention obligations or legitimate reasons require otherwise.
10. Your rights
Subject to legal conditions, you may request access (Art. 15 GDPR), rectification (Art. 16), erasure (Art. 17), restriction (Art. 18), data portability (Art. 20), and object to certain processing (Art. 21). Consent can be withdrawn for the future at any time (Art. 7(3)).
Contact info@electi-venture.de. Since game progress exists only in the local browser, we cannot identify or retrieve your local records through an account.
You may also complain to a supervisory authority, for example the North Rhine-Westphalia Data Protection Authority .
11. Providing data and automated decisions
Technical connection data is needed to load the site. Sudoku entries and settings are voluntary; certain functions require those entries. Consent to analytics and advertising is not required to play. We do not make solely automated decisions with legal or similarly significant effects under Article 22 GDPR in connection with game progress.
12. Changes to this notice
We update this privacy notice when the processing of personal data or the services we use change. The current version is available here at all times. Where required, we obtain renewed consent.
Last updated: 27 October 2026