ADB Says Unauthorized, Offline, or Shows No Device? A Practical USB Debugging Checklist

When adb devices does not show the result you expect, reinstalling random drivers is rarely the best first move. The output already tells you which layer is failing. This checklist separates the most common states: device unauthorized offline An empty device list ADB not recognized by the terminal The goal is to diagnose the connection in a logical order: tool, cable, USB mode, authorization, and finally drivers. Before troubleshooting Make sure the basic setup is correct: Install the latest Android SDK Platform-Tools from Google. Use a USB cable that supports data, not only charging. Unlock the Android phone. Enable Developer options and USB debugging. Connect directly to the computer when possible instead of using an unpowered hub. The location of Developer options differs between Samsung, Xiaomi, Pixel, Huawei, OnePlus, and other interfaces. If you need the device-specific menu paths, this guide to enabling USB debugging on Android phones covers the common manufacturers and the RSA authorization step. Start with one command Open Terminal, PowerShell, or Command Prompt inside the Platform-Tools folder and run: adb devices For extra information, use: adb devices -l A normal result looks similar to this: List of devices attached R58M123ABCD device product:example model:Example device:example The word after the serial number is the important part. What each ADB state means Result Meaning Where to look first device ADB can communicate with the phone The connection is ready unauthorized The phone has not authorized this computer Phone screen and RSA prompt offline ADB sees the device but cannot communicate reliably ADB server, cable, port, or device Empty list The computer is not exposing the phone to ADB Cable, USB mode, driver, or debugging setting adb not recognized The shell cannot find the ADB executable Platform-Tools folder or PATH Case 1: The result is device This is the success state. ADB can send commands to the phone. You can test the connection with a harml