Sidetrack has no server, no account and no analytics. The developer receives no data.

What leaves your browser, and to whom:
- YouTube: the IDs of the videos you add (to fetch titles and chapters) and the videos you play, through YouTube's embedded player.
- GitHub Pages (tom-tour.github.io): the player page and the guest page are loaded from there, so GitHub sees your IP address.
- Rooms, only if you open or join one:
- the public PeerJS server (0.peerjs.com) sees your IP address and the room name, never the messages;
- room members, directly (WebRTC, encrypted): your nickname, identity code, chat messages and guesses; from the host, the playlist and playback position. Members can see each other's IP address. When you block someone in a room, its host learns which person (only people present in that room).
- Public rooms only: an announcement on public Nostr relays (room name, number of players, mode, whether a game is running), signed with a throwaway key per room.

Stored locally only (browser storage): playlists, settings, your identity key and its proof of work, banned and blocked people. Uninstalling the extension deletes all of it.