ADB and Fastboot repair tool

Android ADB device detection dashboard

Find connected Android phones, check ADB or Fastboot state, and fix common USB debugging issues before a flash, unlock, FRP, IMEI, or repair intake workflow.

ADB devices Fastboot devices USB debugging Unauthorized fix
Client PC USB rule: Phones plugged into a customer or technician PC are only visible to ADB running on that same client PC. A public Linux web server cannot see USB phones connected to a visitor's computer through the browser alone.
Desktop workstation available: Use the GSMSharingDev Windows app for local USB detection, ADB/Fastboot pre-checks, guided FRP/unlock/flash workflows, and sync back to your GSMSharing jobs, files, and activity logs.

Step-by-step guide: connect a phone from the client PC

Use this when the phone is plugged into the user's Windows PC USB port. The web page can only detect the phone if GSMSharing or a local connector is running on that same PC with ADB installed.

Browser USB is not enough
1

Install Android Platform Tools on the client PC

Download Android Platform Tools from Google, extract it to C:\Android\platform-tools, and confirm adb.exe exists there.

2

Configure GSMSharing or a local connector

If running this site locally, set DeviceAutomation:ADBExecutable to C:\Android\platform-tools\adb.exe and restart the app. If using the live website, a desktop/helper connector must run on the client PC.

3

Enable USB debugging on the phone

Open Developer options, enable USB debugging, connect with a data USB cable, unlock the phone, and choose File Transfer/MTP if Windows asks for USB mode.

4

Authorize and test ADB on the client PC

Run adb devices from PowerShell, accept the RSA prompt on the phone, then verify the device state says device instead of unauthorized or offline.

5

Return to this dashboard and detect

Refresh this page and press Detect only after ADB works on the same PC where the detection service is running.

Windows PowerShell test C:\Android\platform-tools\adb.exe version C:\Android\platform-tools\adb.exe devices

Demystifying ADB: terminal errors, authorization, and dead Android OS recovery

Use this reference when ADB says command not found, the phone is unauthorized, or the device cannot boot into Android.

Client-side tool required

Part 1: set up ADB and fix terminal errors

  1. Extract Android Platform Tools to C:\Android\platform-tools.
  2. Open PowerShell and move into that folder with cd C:\Android\platform-tools.
  3. In PowerShell, run local tools with .\adb devices. The .\ prefix tells PowerShell to execute from the current folder.
  4. For a permanent fix, add platform-tools to your user PATH, then close PowerShell and open a new session.
PowerShell commands cd C:\Android\platform-tools .\adb devices [Environment]::SetEnvironmentVariable("Path", $env:Path + ";C:\Android\platform-tools", "User")

Part 2: fix the unauthorized device loop

  1. Unlock the phone screen and keep it awake.
  2. When the phone shows Allow USB debugging?, select Always allow from this computer and tap Allow.
  3. If the prompt does not appear, open Settings, Developer options, then Revoke USB debugging authorizations.
  4. Unplug the cable, wait a few seconds, reconnect, and accept the new RSA prompt.
  5. Run .\adb devices again. The status should change from unauthorized to device.

Part 3: when Android will not boot

Regular ADB works only when Android or recovery exposes an ADB service. If the OS is dead or bootlooping, identify the low-level mode first.

Android bootedUse regular ADB.
Samsung Download ModeUse Odin on Windows, or Heimdall on macOS/Linux, with exact model firmware.
Fastboot or BootloaderUse fastboot for Pixel, Motorola, Xiaomi, and similar devices.
Recovery ADB SideloadUse Apply update from ADB, then sideload a compatible factory ZIP.

Low-level flashing protocols

A

Samsung Download Mode

Use Odin or Heimdall. Match the firmware exactly to the model number, then load BL, AP, CP, and CSC packages into their matching slots.

B

Fastboot mode

Check the connection with .\fastboot devices, then flash only firmware images that match the device and bootloader state.

C

Recovery ADB sideload

Select Apply update from ADB in recovery, confirm adb devices shows sideload, then run .\adb sideload firmware.zip.

Examples .\fastboot devices .\fastboot flash boot boot.img .\fastboot flash system system.img .\adb sideload factory_firmware_archive.zip
Can this run fully inside the browser? Partly, but not reliably for every repair workflow. Chromium browsers can support WebUSB-style ADB tools after the user grants permission, but browser USB access is limited, driver-dependent, and not suitable for Samsung Odin Download Mode or many low-level flashing tasks. For professional repair, use a local desktop/helper connector or run GSMSharing locally on the client PC.

ADB and Fastboot requirements

Complete these checks before pressing Detect. They cover Android Platform Tools, OEM USB drivers, data cables, and device authorization.

ADB missing
ADB Not found

adb

Fastboot Not found

fastboot

Mode Server-side ADB runner

USB detection runs on the app host machine.

  1. Install Android Platform Tools on the PC running this app.
  2. Install the OEM USB driver, then reconnect the phone.
  3. On the phone, enable Developer options, turn on USB debugging, and choose File Transfer or MTP USB mode.
  4. Run adb devices once on the PC and accept the RSA prompt on the phone.
  5. Refresh this dashboard and check that the state changes to device.
ADB device not detected Check platform-tools, USB debugging, RSA authorization, and cable mode.
Fastboot device not showing Confirm bootloader mode and install Android Bootloader Interface/OEM drivers.
ADB unauthorized or offline Reconnect USB, revoke debugging authorizations, then approve the phone prompt.

Connected devices

0 devices detected

Idle

No devices detected

Install ADB on the client PC, connect the phone to that same PC, accept the USB debugging RSA prompt, verify adb devices, then refresh detection.

Android ADB and Fastboot detection help

Use this dashboard as a pre-check before Android flashing, unlocking, FRP service, IMEI diagnostics, and remote repair sessions. It does not bypass security; it verifies whether the repair workstation can see the device safely.

Why is my phone not detected?

The phone must be plugged into the same client PC where ADB and the local detection service are running. A remote Linux web server cannot read USB phones connected to a visitor's PC.

What does unauthorized mean?

ADB can see the phone, but the phone has not approved USB debugging. Unlock the phone, reconnect USB, and approve the RSA debugging prompt.

Why does Fastboot not show my device?

Fastboot detection only works while the phone is in bootloader mode. On Windows, install the OEM USB or Android Bootloader Interface driver and use a data-capable cable.

Can public website users connect phones here?

A browser page cannot expose a visitor's USB phone to this ASP.NET server. Public users need a local desktop/helper connector, or they must run GSMSharing locally with ADB installed.