Privacy Policy
Last Updated: October 12, 2026
Fluna ("we," "our," or "us") is a Chrome browser extension that transforms webpages into language learning experiences. We are committed to protecting your privacy and being transparent about our data practices. This Privacy Policy explains what information we collect, how we use it, and your rights regarding your data.
1. Information We Collect
Account Information
Signing in is optional. If you sign in with Google, we receive:
- Your email address (used for authentication and account recovery)
- Your display name and profile picture (shown in the extension)
Language Learning Data
Your vocabulary, the sentences you saved words from, review schedule, streaks, daily goal and language preferences are stored locally in your browser using Chrome's storage. They are not uploaded to our servers.
If you sign in, we store on our servers: the dates you were last active, daily usage counts for the cloud tutor and cloud translation (to enforce daily limits), and your subscription status if you subscribe.
Web Page Content
To detect whether a page is written in the language you are learning, Fluna reads the page's declared language and a short sample of its visible text on pages you open. This check runs on your device with Chrome's built-in language detection; nothing is sent to us. We do not record which websites you visit or collect your browsing history.
When you use Fluna on a page, the text you select or the paragraph you study is processed to provide translations, grammar explanations and questions. See section 3 for where that processing happens.
Usage Analytics
We collect anonymous usage events (for example: install, page activated, word saved, sign-in, upgrade viewed) using a self-hosted, cookie-free analytics service. These events never include page URLs, the text you read or select, or your answers.
2. How We Use Your Information
We use the information we collect to:
- Provide and maintain the Fluna extension and its learning features
- Process text content through AI to generate translations, grammar explanations, and interactive questions
- Track your vocabulary and learning progress across sessions
- Improve our extension and develop new features based on aggregate usage patterns
- Communicate with you about important updates or security alerts
3. AI and Third-Party Services
Fluna prefers Chrome's built-in AI. When it is available on your computer, translations, questions, feedback and grammar explanations are produced on your device and the text never leaves your browser.
When Chrome's built-in AI is not available and you are signed in, Fluna uses a cloud fallback:
- Only the text needed for the request — the words or passage you selected, the question, and your answer (or a transcript of your spoken answer) — is sent to our server and processed with Google's Gemini API
- We do not store this text on our servers, and we do not send your name, email or page URLs to the AI provider
- Google processes these requests under its Gemini API terms
We also use:
- Firebase (Google Cloud) for sign-in and the account data described above
- Stripe to process payments. Your payment details go directly to Stripe and are never seen or stored by us
4. Data Storage and Security
We implement appropriate technical and organizational measures to protect your personal data:
- Account data is stored in Firebase (Google Cloud) with encryption at rest and in transit
- Authentication is handled through secure Firebase Authentication
- Extension settings and preferences are stored locally in your browser using Chrome's storage API
- We do not store webpage content on our servers
While we strive to use commercially acceptable means to protect your data, no method of transmission over the Internet or electronic storage is 100% secure.
5. Permissions
Fluna requests the following browser permissions:
- Access to websites: to detect pages in the language you are learning and show Fluna's learning tools on them
- Scripting and Active Tab: to add Fluna's interface to the page you are reading
- Web Navigation: to notice page changes in single-page websites
- Storage: to save your preferences, vocabulary and progress locally
- Side Panel: to show your vocabulary and reviews
- Alarms: to keep the "words to review" count up to date and schedule reminders
- Identity: to let you sign in with Google
- Notifications (optional): requested only if you turn on the daily review reminder
You can stop Fluna on any website with "Ignore this site" in the extension menu.
6. Data Retention
We retain your data for as long as your account is active. If you delete your account, we will delete your personal data within 30 days, except where we are required to retain it for legal obligations. Anonymous, aggregated analytics data may be retained indefinitely as it cannot be linked back to individual users.
7. Your Rights
You have the right to:
- Access the personal data we hold about you
- Correct any inaccurate personal data
- Delete your account and associated data
- Export your vocabulary and learning data
- Withdraw consent by uninstalling the extension at any time
To exercise any of these rights, please contact us at the email address below.
8. Children's Privacy
Fluna is not directed at children under the age of 13. We do not knowingly collect personal information from children under 13. If we discover that a child under 13 has provided us with personal information, we will delete it promptly.
9. 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 updated policy on this page and updating the "Last Updated" date. We encourage you to review this Privacy Policy periodically.
10. Contact Us
If you have any questions, concerns, or requests regarding this Privacy Policy or our data practices, please contact us at: