Privacy

Last changed 9 October 2026.

This covers Tern, the app for Android; Tern Mesh, the app for iPhone, iPad and Mac; and this site. The project collects nothing about the people who use them: there is no account, no analytics and no advertising. What does leave your device for the internet is a request to this site, when you visit it or when an app looks for firmware, and the map's tiles, when you open the map. Cloudflare, which serves the site, sees the first, as any host does; who serves the map is set out below.

The apps

Both apps work the same way, except where this says otherwise.

• Your messages, contacts and groups are held by your node and kept on your device, so that the app can show them. They go between nodes by radio. They do not pass through, and are not stored on, any server of the project's.
• Bluetooth is how the app talks to your node, and is used for nothing else.
• Your location is used only if you share your position with a contact or a group, and the app asks for it only then. While your node shares with anyone, the app gives it the phone's location, and the node rounds it to what each one was chosen to see before anything goes on the air. It is given to nothing else. On Android 11 and earlier, Android also asks for location before an app may look for Bluetooth devices; the app uses that permission to find your node.
• The camera, on a phone or iPad, reads the QR code of a contact you are adding. The app keeps no picture and sends none anywhere.
• Firmware: when you look for an update to your node's firmware, the app fetches the list of releases, and then the firmware, from this site. Those requests carry what any request to a website does: the address they come from and the file asked for, which for the firmware is the one for your node's board and region. They carry nothing else about you or your node.
• The map fetches its tiles while you look at it. The Android app's come from OpenFreeMap, which sees what any request to a website carries, the address it comes from, and which areas the map shows, and nothing else of yours. The Apple app's map is Apple's own, through MapKit, which Apple handles under its privacy policy.

The apps use the internet for nothing else. Removing an app removes everything it kept on the device. The Android app is left out of Android's backups and of moving to a new phone: the next time it connects, your node gives it back what it holds.

This site

The site is static files, with no cookies and no analytics of its own. What theweb app remembers, it keeps in your browser. It asks the browser for your location only when you share your position, and gives it to your node alone, while the page is open, as the apps do. It shows a position received on a map only if you follow its Map link, which opens OpenStreetMap with that position in the address. When the node can be updated, it asks this site for the list of releases and then for the firmware, as the apps do. The site is served by Cloudflare, which, like any host, sees the address a request comes from and what was asked for, and handles that underits own privacy policy.

Changes and questions

If this changes, the new text and its date will be here, and the change will be in thesite's history. Questions go to the issue tracker of theAndroid app, theApple app or the site.