BlauBerry

Privacy Policy

Last updated: August 2026

1. Introduction and Scope

BlauBerry ("we", "our", or "us") operates the blauberry.app website and web app, and publishes the BlauBerry Chrome Extension ("Từ điển Đức-Việt BlauBerry") on the Chrome Web Store. This Privacy Policy explains how we collect, use, disclose, and safeguard your information. It applies to all of the following, together referred to as the "Services":

  • The blauberry.app website and web app;
  • The BlauBerry Chrome Extension and any other browser extension we publish.

2. Information We Collect

We collect information you voluntarily provide when you register for an account, including your email address, display name, profile picture (if you sign in with Google), your native language, and your German proficiency level. We also collect the learning data you create — saved words and sentences, collections, notes, exercise answers, and progress.

3. How We Use Your Information

We use the information we collect to: provide and maintain the Services, authenticate you, personalize your learning experience, track your progress and adapt content to your level, respond to your support requests, communicate with you about updates and new features, detect abuse and secure our systems, and improve our products based on aggregated usage patterns.

4. Legal Bases for Processing

Where the GDPR applies, we process your data on the following legal bases: performance of a contract (providing the Services you signed up for), your consent (optional analytics, marketing email), our legitimate interests (security, abuse prevention, product improvement), and compliance with legal obligations.

5. Chrome Extension — What It Is and What It Does

The BlauBerry Chrome Extension is a German-learning tool that works on top of the page you are already reading. When you select German text, it can show a dictionary entry, a Vietnamese or English translation, a grammar explanation, or save the text to your vocabulary collection. On YouTube it can show translated subtitles. Because the extension is designed to work on any page where you might read German, it requests permission to run on the sites you visit.

6. Chrome Extension — Data Accessed on Web Pages

The extension reads page text on demand, in response to your action — it does not continuously scan, index, harvest, or upload the content of the pages you browse. It processes the following data from the page you are viewing, and only for the purpose described:

  • Selected text (Website Content). When you highlight text, double-click a word, use the Alt+D shortcut, or use the right-click menu, the selected text is sent to our processing services for dictionary lookup, grammar analysis, or translation — see the Third-Party Services section for the kinds of processor involved. Nothing is sent until you trigger a lookup.
  • The sentence around your selection, when you use "Ask AI". To explain a word in context, the extension also reads the sentence that word appears in, up to 600 characters; for a longer selection it uses up to the first 3,000 characters of the text you selected. That text is placed in the question and opened in a new blauberry.app tab, so it also appears in that tab's address. We use it only to answer your question.
  • YouTube subtitle text. If you enable the YouTube subtitle feature, the subtitle lines of the video you are watching are sent for translation so they can be displayed bilingually. This runs only on youtube.com and only while the feature is on.
  • The hostname of the current tab. The extension reads the hostname (for example "spiegel.de") locally, in your browser, so it can honour the per-site on/off switch. The hostname is not sent to our servers and is not included in analytics events.
  • Text you save. Words, sentences, and notes you explicitly choose to save are stored in your BlauBerry account so they appear in your collections on the web app.

7. Chrome Extension — What We Never Collect

We want to be explicit about the limits. The BlauBerry Chrome Extension does not collect, store, or transmit:

  • Your browsing history, the list of sites you visit, or the URLs of pages you open;
  • Passwords, login credentials, or anything you type into a password field;
  • Payment card numbers, bank details, or other financial information;
  • Form input, keystrokes, cookies, or session tokens belonging to other websites;
  • Screenshots, screen recordings, microphone, camera, or location data;
  • Health information, personal communications, or any page content beyond what is described in the section above.

8. Chrome Extension — Local Storage on Your Device

The following is stored locally in your browser using the chrome.storage API and stays on your device unless stated otherwise:

  • Your settings (trigger mode, target language, audio autoplay, subtitle size, analytics opt-in, and the list of sites where you turned BlauBerry off);
  • Your recent lookup history — up to 200 entries, kept locally so you can revisit recent words. It is never uploaded to our servers, and you can clear it at any time from the extension;
  • A randomly generated device identifier (a UUID) used only to count anonymous usage when analytics is enabled. It contains no personal information;
  • Your API key. The extension has no login screen of its own: when you connect it, the BlauBerry web app issues a scoped API key that is stored in chrome.storage.local and sent only to api.blauberry.app. Signing out from the extension revokes that key on our servers and deletes it from your device.

9. Chrome Extension — Permissions and Why We Need Them

The extension requests the minimum set of permissions required for its features:

  • "storage" — to keep your settings, local history, and API key on your device;
  • "contextMenus" — to add the "Look up with BlauBerry" and "Ask AI about this" entries to the right-click menu;
  • Host access to http and https pages — so the lookup popup can appear on the page you are reading when you select text;
  • api.blauberry.app — to look up words, save vocabulary, and reach the AI tutor;
  • A machine-translation service — to translate selected sentences and YouTube subtitles;
  • us.i.posthog.com — to send product analytics, only if you leave analytics enabled.

10. Chrome Extension — Analytics and User Activity

To fix bugs and improve the product, the extension can send product-analytics events to PostHog. They are anonymous while you are signed out and tied to your account once you sign in. These events record that an action happened and basic non-identifying attributes — for example "a word was looked up", the character length of the text, whether a dictionary entry was found, which target language was selected, or which setting was changed.

  • Analytics events never include the text you looked up or translated, the page URL, the page title, the hostname, or any page content.
  • If you are signed in, events are associated with your BlauBerry user id and email so we can support your account; if you are not signed in, they use only the random device identifier.
  • You can turn analytics off at any time in the extension's options page. When it is off, no analytics requests are sent at all.

11. Chrome Web Store Limited Use Disclosure

BlauBerry's use of information received from Chrome Extension APIs and Google APIs adheres to the Chrome Web Store User Data Policy, including the Limited Use requirements. Specifically:

  • We do not sell user data to third parties, data brokers, or information resellers.
  • We do not transfer or use user data for serving personalized, targeted, or context-based advertisements.
  • We do not transfer or use user data for creditworthiness determination or lending purposes.
  • We do not allow humans to read user data, except: (a) with your explicit consent for a specific issue you reported, (b) when necessary for security purposes such as investigating abuse, or (c) when required to comply with applicable law.
  • We only use user data to provide and improve the core functionality of the BlauBerry Chrome Extension — providing German dictionary lookups, translations, saved vocabulary, and AI language-learning assistance.

Chrome Web Store User Data Policy

12. Data Storage, Security, and International Transfers

Your data is stored on cloud infrastructure operated by our hosting providers and may be processed in countries other than your own, including within the European Union and the United States. All traffic between the Services and our servers uses HTTPS. We implement appropriate technical and organizational measures — access control, encryption in transit, and least-privilege API keys — to protect your information against unauthorized access, alteration, disclosure, or destruction.

13. Data Retention

We keep your account data for as long as your account is active. Local extension data (settings, lookup history, device id, API key) lives on your device until you clear it or uninstall the extension. Extension API keys expire automatically and are revoked immediately when you sign out. Analytics events are retained in aggregate form. When you delete your account, we delete or anonymize your personal data within 30 days, except where we are required to retain it by law.

14. Cookies and Tracking

The blauberry.app website uses cookies and similar technologies, including essential cookies for authentication and site functionality and analytics cookies to understand how visitors use the site. Unlike the extension, website analytics does record the pages you view and the interactions you make on them, and links that activity to your account when you are signed in. You can control cookie preferences through your browser settings. The Chrome Extension does not set tracking cookies and does not read cookies belonging to the websites you visit.

15. Third-Party Services

We rely on a small number of third-party processors, each of which has its own privacy policy governing the use of your information. They fall into these categories: authentication and account storage, machine translation, product analytics, bot protection and content delivery, and cloud hosting. Each processor receives only the data it needs to perform its function.

16. Your Rights

You have the right to access, correct, export, or delete your personal data, to withdraw consent for optional processing such as analytics, and to object to or restrict certain processing. You can delete your local extension data from the extension itself, and you can request account deletion or a data export by emailing [email protected]. If you are located in the EU or the UK, you also have the right to lodge a complaint with your local data protection authority.

17. Children's Privacy

Our Services are not directed to children under 13. We do not knowingly collect personal information from children under 13. If you believe we have collected such information, please contact us immediately and we will delete it.

18. Changes to This Policy

We may update this Privacy Policy from time to time. We will notify you of any material changes by posting the new Privacy Policy on this page and updating the "Last updated" date above. Continued use of the Services after a change means you accept the updated policy.

19. Contact Us

If you have questions about this Privacy Policy or about how the BlauBerry Chrome Extension handles your data, contact us at [email protected]. We aim to respond within 5 business days.