Everyone must be on the same network: the same Wi-Fi, or the host’s hotspot.
Questions and fixes
Does everyone need to be on the same network?
Yes. Everyone joins the same Wi-Fi, or the host’s hotspot. LocalJam never uses the internet, so devices on different networks can’t reach each other.
The jam doesn’t show under Nearby
Join with the QR code or link instead. Nearby uses mDNS, which hotspots, guest Wi-Fi and many office networks block.
Nobody can connect at all
The network probably isolates devices from each other (“AP isolation” or “client isolation”, common on guest and public Wi-Fi). Use a home network or a phone hotspot.
How do I use a hotspot?
One phone turns on its hotspot and the others join it. Then host on the hotspot phone and share the QR code.
A guest drifts or sounds late
Use the sync nudge to move that device’s sound earlier or later. On Bluetooth headphones and speakers some delay is expected: LocalJam compensates only as far as the device reports it, and the nudge covers the rest by hand.
Can someone listen without installing the app?
Yes. They scan the host’s QR code and listen in their browser, from a page the host’s phone serves on the local network. Browser guests listen only; they can’t add songs or host.
Keep the tab open and in front: a backgrounded tab or a locked screen may stop playing. Safari can’t play Ogg Vorbis or Opus files.
Which audio files play?
Android, iOS and macOS play whatever the system decodes. Windows and Linux play mp3, flac, wav and ogg only; m4a/AAC isn’t supported there yet.
What happens if the host leaves?
The jam ends. There is one host per jam, and the host’s device is the one serving the songs.
Hosting on a desktop
Allow LocalJam through the firewall for incoming connections on private networks.
The host listens on one TCP port, which the system picks fresh each time a jam starts. It carries the WebSocket, the audio and the browser page. Nearby discovery uses mDNS on UDP 5353. Because the TCP port changes, allow the app in your firewall rather than a fixed port.
Who can join my jam?
A jam left discoverable under Nearby can be joined by anyone on the same network. Turn Nearby off to admit people only by QR code or link. Traffic on the network is plain HTTP gated by a random session token, so use networks you trust, such as your home Wi-Fi or your own hotspot.
Can I switch between the GitHub APK and the Play Store version?
Not by updating. The two are signed with different keys and can’t update each other. Uninstall one before installing the other. Uninstalling removes the app’s data on that device, including jam history.
Report an issue
Found a bug, or something that doesn’t match this page? Open an issue on GitHub. Include the app version (Settings → Version), the devices involved, how they were connected (home Wi-Fi, hotspot, guest network) and the steps that lead to the problem. Please leave out anything private.
Real-device test reports are especially welcome: physical phones, Windows and Linux are where LocalJam has been tested least.
Security problems
Please don’t open a public issue for a vulnerability. Use GitHub’s private vulnerability reporting instead: Security → Report a vulnerability on the LocalJam repository. What counts, and what doesn’t, is in the security policy.