Demirline
Demirline is a Chrome extension that helps you learn languages on YouTube and other web pages. This policy explains what data the extension processes and where it goes.
1. Summary
- Demirline has no backend and no user accounts of its own.
- Your API key and settings are stored in the browser (
chrome.storage.local). - Text for translation and dictionary lookups is sent only to the AI provider you select.
- The API key is never passed to content scripts or the web page; AI calls run only in the background service worker.
2. Data we store or process
Locally in the browser
- Extension settings (provider, model, target language, hotkeys, UI language, feature toggles)
- The API key you enter
- Translation cache (to avoid re-requesting the same sentences)
This data stays in your Chrome profile on your device. Demirline does not upload it to a Demirline cloud.
Data sent when you use features
- Text to translate (caption sentences, selected words/sentences/paragraphs) — to your chosen AI API
- YouTube caption tracks — read from the watch page (same-origin / Innertube) for dual subtitles; relevant text may be sent to the provider for translation
3. Third-party services
Depending on your settings, requests may go to:
Those providers process data under their own policies. Your API key and billing are your responsibility. YouTube is operated by Google; video and caption content are subject to Google’s terms.
4. Permissions
storage— settings and cache- YouTube host access — captions and page integration
- AI provider host access — translation requests
<all_urls>content script — for paragraph/word/sentence features only; text is processed when you use the hotkey or selection
5. Sale and advertising
Demirline does not sell your personal data, run an ad network, or include third-party analytics trackers in the extension (this marketing site is kept intentionally simple).
6. Children
The extension is not directed at children under 13. We do not knowingly collect personal data from children.
7. Deleting your data
Removing the extension from Chrome removes its local storage. You can also clear or change your API key in Settings. For provider-side logs, refer to that provider’s policy.
8. Changes to this policy
If features or data flows change, we will update this page and the effective date when material.
9. Contact
Privacy questions: support@demirline.com