VIDEO SENSEI · CHROME EXTENSION
Extension Privacy Policy
Last updated: October 11, 2026
This notice explains what the Video Sensei Chrome extension handles, why it handles it, where information goes, and the controls available to you.
1. What the extension does
Video Sensei helps you read and understand the YouTube video you choose: timestamped transcripts, bilingual reading, learning highlights, word and expression explanations, grammar, chapter outlines, evidence-linked knowledge maps, suggested learning questions, video recommendations, and saved bookmarks. The Chrome extension and the Video Sensei website use the same account and learning library.
The extension does not capture screenshots or run practice exercises. Those features are available separately in the website app. This notice covers the Chrome extension and the account services it uses; the website privacy notice describes additional website features.
2. Information we handle and why
Account information: your email address and password are submitted to Supabase Auth when you register or sign in. Your account identifier and login session let you access your private library. The extension does not save your password. Supabase handles authentication credentials and account verification according to its service settings.
Video and learning information: when you open or use the learning panel on a supported YouTube video, the extension reads its URL or video identifier, title, duration, and current playback time. It handles the transcript, exact selections and timestamps, selected languages, translations, highlights, explanations, chapter outlines, knowledge maps, learning questions, and search terms to provide the learning features you request.
Your saved information: bookmarks contain selected source text, its source and time, translations, explanations, categories, and any personal notes you enter. These records are stored locally and synchronized with your authenticated Video Sensei library. The service also records daily video usage and pending task information to enforce the free allowance, prevent duplicate work, and keep the service reliable.
The extension does not collect a general browsing history, read unrelated websites, or upload a list of your other tabs. It does not include advertising trackers, tracking pixels, or a third-party analytics SDK. Hosting and authentication providers may process network information such as IP addresses, request times, and operational or security logs.
3. Where information goes
Video Sensei at www.videosensei.space processes learning requests and connects them to the shared account library. Supabase provides authentication, database storage, and private image storage. Account requests and bookmark synchronization can connect directly from the extension to the Video Sensei Supabase project.
To obtain captions, the server sends the selected video identifier and subtitle language to YouTube Transcriptor through RapidAPI. To prepare sentences, translate, create highlights, chapter outlines or knowledge maps, explain a selection, and assess recommendation passages, the server sends the relevant transcript text and context and your learning language to the OpenAI API. Provider API keys stay on the server; users do not need to enter their own keys.
When you request more videos from YouTube, the server sends search queries based on the selected learning question and the content language to the YouTube Data API. It may fetch candidate captions and send relevant passages and the learning question to OpenAI to assess their relevance. Search candidates are distinguished from transcript-backed clips; loading another video in the extension uses the same video allowance.
Vercel hosts the Video Sensei service and may retain operational and security logs. YouTube continues to serve the video page and player under its own privacy practices. Clicking an app link opens the Video Sensei website, where its authentication cookies and website privacy notice also apply.
These providers may process information outside your country. We use them to supply the disclosed learning, account, storage, and hosting features; their own privacy and retention terms also apply. We do not sell your personal information or share it with advertising platforms or data brokers.
4. Local storage and account security
Language and display preferences remain in ordinary browser storage. Local bookmark records, including their source snapshots, explanations, personal notes, and any older saved images, are encrypted with AES-256-GCM. The encryption key is stored as a non-extractable key in the extension’s IndexedDB. This protects stored record contents, but does not protect against someone who has compromised your browser profile or device.
Access and refresh tokens for new login sessions are kept only in Chrome’s in-memory session storage, restricted to trusted extension contexts. They are not returned to the side panel, inserted into exports, or sent to YouTube. Browser restart or extension reload or update clears this session storage, so you will need to sign in again. Temporary transcript and reading caches also remain in session memory.
Requests to Video Sensei and its service providers use HTTPS. Cloud account data is protected by authentication and user-specific database access rules. No storage or transmission method can promise absolute security.
When you request a notebook export, its bookmark and source data is written to an ordinary, unencrypted file, including the language recorded with each bookmark. Exports exclude passwords, authentication tokens, and encryption keys. Keep exported files private; they remain wherever you choose to save them.
Signing out clears the local login session and visible account state and attempts to revoke the session on the server. An already issued access token can remain valid until its expiry. Signing out does not delete your cloud library, locally cached bookmark records, or previously exported files.
5. Older local bookmarks and images
If an earlier version left guest bookmarks on your device, they are not automatically uploaded merely because you sign in. You can review them and explicitly confirm an import into your account. Failed changes may stay locally pending until synchronization succeeds; conflicts are shown for review.
Earlier versions may have stored bookmarks or login tokens without encryption in local Chrome storage. On upgrade, the extension transfers an older login session to memory and encrypts older notebook records. It removes the old local copy only after verifying the new copy. If migration fails, the older data is retained and the affected operation is blocked for retry; corrupt encrypted notebooks are not silently overwritten.
The extension can display existing account images and synchronize images already included in older saved notes. An explicitly confirmed import of older notes may therefore upload their existing images to private Supabase storage. This does not give the extension a screenshot capture feature; it cannot create new screenshots.
6. Your choices, retention, and deletion
You choose which video to load, which text to explain, and which bookmarks or notes to save. You can edit or remove bookmarks and export the visible notebook. You can sign out, clear extension storage, or uninstall the extension to remove the local session or local copies; these actions do not delete cloud records or exported files.
Cloud learning materials and saved records remain in your account until removed through available controls or handled through a verified data request. Removing a bookmark does not automatically delete its original transcript, other learning records, or previously uploaded image files. The interface does not currently offer a complete account-deletion or cloud-export workflow.
Use the contact below to request access, correction, account or data deletion, or information about retention. We may need to verify account ownership before handling a request. Operational logs, backups, and provider-held records follow the relevant service settings and retention practices; deletion is not a promise of immediate removal from every backup or provider system.
7. Limited Use
Video Sensei uses information received from Chrome APIs in accordance with the Chrome Web Store User Data Policy, including its Limited Use requirements. We limit use to the disclosed video-learning features and their operation, security, and reliability.
We transfer user data only as needed to provide these features, meet applicable legal requirements, or protect against fraud and abuse. We do not use or transfer it for personalized advertising, resale, creditworthiness, or lending. Human access to private user data is limited to your explicit consent for specific support, permitted aggregated and anonymized operational information, necessary security investigation, or legal requirements.
8. Changes to this notice
We will update this page when the extension’s data handling changes and show the revised date above. A new purpose for collecting or using information will be disclosed before that change is used.
Support and privacy contact
Publisher: Yiyi Builds
For questions, technical support, or account and data requests, email yi.wang.ed.ai@gmail.com.