Last updated: October 9, 2026
The Altffour app
The app connects to the Jellyfin server you choose. Your library, watch history, favourites and settings are kept on that server. The app saves your preferences there too, so they follow you between devices.
Like any Jellyfin server, the server's admins can see who is watching what, on which app and device. If the server runs Jellyfin's Playback Reporting plugin, they can also see past plays. The Altffour app's admin panel shows the same information. It adds nothing new.
If your server takes requests, its admins see what you asked for.
Searching for titles that aren't on your server sends your search words to TMDB from the server, not from your device.
On your device, the app keeps:
- the server address, your Jellyfin sign-in and a device ID, so you stay signed in and your devices can be signed out one by one;
- your settings and theme;
- cached pages and artwork, so screens open quickly;
- anything you download to watch offline.
Signing out, removing downloads or clearing the app's data removes these from your device.
The app shows no ads and has no analytics or tracking.
Other services the app uses
- Trailers play through YouTube's privacy-enhanced mode (youtube-nocookie.com) when you watch or preview one. When a trailer loads, YouTube receives your IP address and browser details and may store data on your device for that player, under Google's privacy policy.
- Casting: when you use the Cast button, Google's Cast software runs in your browser and on your Cast device.
- Fonts for the web app load from Google Fonts.
- Ratings, reviews and artwork (for example from TMDB and OMDb) are fetched by your Jellyfin server or its Companion plugin. If you add your own TMDB or OMDb keys in the app's settings, they're kept in your server preferences and used only for you, on your server.
The Companion plugin
Companion runs on the server owner's own Jellyfin server and keeps its data there. It sends nothing to Altffour. To do its work it may look up titles with public services: TMDB and OMDb for details and ratings, AniSkip and IntroDB for intro, recap and credits markers, an anime id mapping service (arm.haglund.dev), public subtitle services, and IGDB for game details. It also reads any catalogue address the server owner sets. These lookups send title ids, not who is watching.
Keeping and removing data
Your library, history and settings are on your Jellyfin server; its owner can change or delete them. To ask us about data we hold, or to have it corrected or deleted, ask in our Discord server or email support@altffour.com. We'll answer within 30 days.
Children
This site, the Altffour app and the Companion plugin aren’t directed at children under 13, and we don’t knowingly collect their personal information.
Changes
If this policy changes, the date above changes with it. Questions: our Discord server or support@altffour.com.