Last updated: July 2026 · Deutsche Version
This privacy policy applies specifically to the "LinguaFlow for YouTube" browser extension (the "Extension"). For the LinguaFlow apps and website, our general privacy policy also applies.
Data controller: LinguaFlow e.U., Linzer Straße 17, 4100 Ottensheim, Austria · Email: hello@linguaflow.app
1. What the extension does
The Extension overlays a word-for-word translation of the subtitles of the YouTube video you are currently watching, in your native language (the Birkenbihl method). To do this, it reads the subtitles of the current video and has them translated by our server.
2. Data we process
- Subtitle text of the current video. The Extension captures the subtitle text of the video you are watching and sends it to our translation function to produce the word-for-word translation. Only the plain text is transmitted (no timestamps). This text is processed only transiently in memory for the current video and is not stored persistently.
- Account data. To sign in, you use an email address (email/password, Google, or Apple sign-in). We process your email address and authentication tokens to authenticate you to the translation service and to associate your subscription.
- Usage counter. We count how many videos you have translated in order to enforce the free tier and your subscription status (including abuse protection). We do not store the titles or contents of the videos — only counts per account.
- Payment data (only when subscribing). If you purchase a subscription, payment is handled by our reseller Paddle.com. We do not receive or store your full card details.
- Extension settings (learning/target language, font size) are stored locally in your browser.
3. Purposes and legal bases
- Providing the translation feature (performance of a contract, Art. 6(1)(b) GDPR).
- Sign-in, subscription management, and enforcing the free tier (performance of a contract and legitimate interest in abuse protection, Art. 6(1)(b) and (f) GDPR).
- Compliance with legal obligations, e.g. accounting (Art. 6(1)(c) GDPR).
4. Recipients / services used (processors)
- Google Firebase (authentication + database) – for sign-in and the usage counter.
- DeepL (primary translation service) and Google Cloud Translation (fallback for languages DeepL does not support) – the subtitle text is sent server-side to these services to produce translations.
- Paddle.com Market Ltd – payment processing when subscribing (Merchant of Record).
Processing happens via a server function in the EU (region europe-west1). Where data is processed outside the EU, this is safeguarded by appropriate measures (e.g. EU Standard Contractual Clauses).
5. What the extension does NOT do
- It does not read any other websites – it is limited to YouTube and the sign-in domain.
- It does not collect your browsing history or general browsing activity.
- It shows no advertising and does not sell any data.
- The data processed is used solely to provide the translation feature, not for advertising or profiling.
6. Retention
Subtitle text is processed transiently and not stored. Account and usage data are kept for as long as your account exists or as long as legal retention obligations require.
7. Your rights
You have the right to access, rectification, erasure, restriction of processing, data portability, withdrawal of consent, and objection. To exercise these, contact hello@linguaflow.app. You also have the right to lodge a complaint with a data protection authority (in Austria: Datenschutzbehörde).
8. Security
Communication with our servers is encrypted (HTTPS). We use appropriate technical and organizational measures to protect your data.
9. Changes
We may update this policy as needed. The current version is always available at linguaflow.app/privacy-extension.html.
10. Contact
LinguaFlow e.U.
Linzer Straße 17, 4100 Ottensheim, Austria
Email: hello@linguaflow.app