LinguaCap ("the Extension") is a browser extension that provides dual subtitle display and word translation for video and music streaming services. This policy explains what data the Extension collects, how it is used, and your choices.
Anonymous session. On first use the Extension creates an anonymous account via Supabase Auth. This generates a random user ID (UUID) used solely for rate limiting translation requests. No email, name, or personally identifiable information is collected.
Device ID. A random UUID stored locally in Chrome storage to identify the installation. It is never sent to third parties.
Saved words. Words you save to the dictionary are stored locally in Chrome storage on your device. They are never uploaded to any server.
Translation requests. When you click a word or enable auto-translate, the text is sent to our Supabase Edge Functions which call third-party AI and translation APIs (Google Translate, Groq, Google Gemini). Only the word or subtitle line is sent — no page URLs, browsing history, or personal data.
User preferences. UI language, style settings, and feature toggles are stored locally in Chrome storage.
Browsing history or page URLs
Cookies or authentication tokens from visited websites
Video or audio content
Personal information (name, email, address)
Keystrokes or form data
Translation requests are processed through:
Google Translate (unofficial API) — for line-level subtitle translation and word lookup
Groq API — for detailed word translation via AI
Google Gemini API — for lyrics batch translation
Supabase — for anonymous authentication and edge function hosting
Upstash Redis — for rate limiting (stores only anonymous user ID and request counts)
These services may process the text you translate according to their own privacy policies.
All user data (saved words, preferences, session tokens) is stored locally in Chrome's chrome.storage.local. The Extension does not maintain a database of user data on any server.
Local data persists until you uninstall the Extension or clear it manually.
Rate limit counters on the server expire automatically after 12 hours.
Anonymous session tokens are refreshed automatically and are not linked to any personal identity.
webRequest — to detect subtitle file downloads (VTT/SRT) from streaming services
storage — to save user preferences and dictionary locally
activeTab — to interact with the current tab's video player
scripting — to inject subtitle overlay into video pages
host_permissions (*://*/*) — required because subtitle URLs vary across streaming platforms and CDN domains; the Extension only activates its features on supported sites (YouTube, Netflix, Spotify, Yandex Music)
The Extension is not directed at children under 13 and does not knowingly collect any personal information from children.
We may update this policy from time to time. Changes will be posted on this page with an updated effective date.
If you have questions about this privacy policy, please open an issue on our GitHub repository or contact us at: baursaqdev@gmail.com
Effective date: April 11, 2026