What you need
- A phone farm box (for example 20 × Samsung S9, S10 or S20 boards) with its power supply and USB cable.
- A computer running Windows 10/11, macOS 12+, Linux or ChromeOS.
- Google Chrome, Microsoft Edge or Opera. Safari and Firefox can’t access USB devices.
- For more than one box: a powered USB 2.0/3.0 hub, so every box gets enough bandwidth and power.
1. Power on the box and choose USB mode
Most boxes have a mode switch with a coloured light: blue usually means USB mode, green means OTG/LAN (network) mode. Start in USB mode and connect the box to the computer with the supplied cable, straight into the computer or into a powered hub. Later you can switch to OTG/LAN mode with network mode.
Boards in phone farm boxes ship with USB debugging already enabled. Don’t factory-reset them or switch debugging off, or you’ll need to re-authorize every board.
2. Free the phones from other tools
A USB phone can be used by only one program at a time. If CXT Group Control, Total Control, scrcpy, Android Studio or an adb server is running, quit it first. If you’ve used adb on this computer, run:
adb kill-server3. Import the box’s ADB key (screenless boards)
Phones only accept ADB connections from computers they trust. Normal phones show an “Allow USB debugging?” prompt — but boards without a screen can’t. PhoneFarm already includes the public box keys that sellers publish (for example the CXT key), so most boxes connect with nothing to do. If yours still says “waiting for permission”, give PhoneFarm the same key as the computer that set up the box. See how to import your ADB key; it takes one minute.
4. Add the phones in your browser
- Open PhoneFarm and click Add USB phones.
- Chrome lists the USB devices it can see. Pick a phone and click Connect.
- Click Add USB phones again for the next one. Already-connected phones are hidden from the list so you can move quickly.
You only do this once per phone. From then on, PhoneFarm reconnects every allowed phone automatically when you open the page or plug the box back in.
5. Number and group your phones
PhoneFarm gives each phone a number. Select phones and use Name / number / group… to renumber them in the order they sit in the box, give them names like Box A {nn}, and put each box in its own group. The number pad in the sidebar then selects any phone, or a range of phones, by its number.
6. Control them all
- Select phones (Ctrl/⌘ + A selects all) and turn on Sync.
- Double-click a phone to open it large. Everything you do there is mirrored on the selection.
- Use the toolbar for batch jobs: install APKs, send files, type text from Excel, run ADB commands, take screenshots.
Troubleshooting
| Problem | Fix |
|---|---|
| Phone shows “In use by another program” | Quit other phone tools and run adb kill-server, then click Reconnect. |
| Chrome’s picker is empty on Windows | Windows needs a WinUSB driver for ADB devices. Install Google’s USB driver or the box vendor’s ADB driver once. |
| Picker is empty on Linux | Add udev rules for Android devices (for example the android-sdk-platform-tools-common or android-udev-rules package), then replug. |
| Only some phones appear | Use a powered hub, a short data cable, and avoid chaining more than two hubs. |
| Waiting for permission | Import the adbkey file, or tap “Always allow” on phones that have a screen. |
Ready? Open PhoneFarm — or try the 40-phone demo first.