Last updated: May 11, 2026
Duet is a browser extension that synchronizes play, pause, and seek events for two people watching the same video. This document describes exactly what data the extension touches, where it goes, and how long it lives.
The extension transmits nothing until you click Create a room or Join room in the popup. After that, while you remain in a room:
| Data | Purpose |
|---|---|
| 6-character room code | Identifies the room you and your partner share |
| URL of the page with the active video | So both sides can detect they're on the same page and so the popup can show what your partner is watching |
| Hostname and page title | Shown in the partner card |
currentTime, duration, paused, playbackRate |
Drives the actual sync |
| Display name and avatar emoji | Labels your actions to your partner ("Alice paused") |
| Reactions and short chat messages | Delivered to your partner; auto-deleted from the database 6 seconds after they're sent |
| Randomly generated session user ID | Lets us tell your events apart from your partner's |
The extension does not read or transmit form contents, passwords, autofill data, bookmarks, history from other tabs, or anything from the page outside of the active <video> element and the page's URL/title.
All transmitted data is written to a Firebase Realtime Database hosted in Google Cloud (US-Central region) and managed by Duet's developer. Access to the project is restricted to the developer; the database is not publicly browsable.
Within the database, all data lives under the room code. Lifetimes:
The developer does not analyze, export, or sell the contents of the database. The data is read by Firebase's realtime infrastructure solely to deliver each side's events to the other side.
Inside your browser's chrome.storage.local:
These never leave your computer. They are removed when you uninstall the extension.
Saves your display name and current room locally so you don't have to retype them.
Identifies which tab the video is in so play/pause events go to the right place.
Injects the sync logic into every frame of a video page (some sites put the player in a cross-origin iframe) and routes messages to the correct frame.
Duet works on any site with an HTML5 <video> element. This permission is required to detect a video regardless of the site you're on. The extension reads only the video's playback state, the page URL, and the page title.
Duet is not directed at children under 13 and does not knowingly collect data from them.
If this policy changes in a material way, the new version will ship in a release of the extension and be visible in the GitHub repository. The "Last updated" date at the top will move.
For questions about this policy, open an issue on the Duet GitHub repository.