adb-kill-server

Kill the adb server if it is running

$ adb kill-server

adb-kill-server

(None)
    This specific command does not accept any direct parameters or options. Its execution triggers the immediate termination of the ADB server process without requiring further arguments.

The adb-kill-server command is a fundamental utility within the Android Debug Bridge (ADB) toolkit. Its primary function is to immediately stop the ADB daemon server process that runs in the background on your development machine. This server is essential for managing all communication between your computer and connected Android devices or emulators.

When you execute any adb command (like adb devices or adb shell), the system first checks if an ADB server is running. If not, it automatically starts one. However, sometimes the server can get into a corrupted or unresponsive state, leading to issues such as devices not being detected, 'device offline' errors, or general communication failures. In such cases, adb-kill-server provides a quick and effective way to force a shutdown of the problematic server. After killing the server, the next adb command you run will typically start a fresh, clean instance of the server, often resolving the underlying communication problems and restoring proper ADB functionality. It is a crucial first step in many ADB-related troubleshooting scenarios.

The adb-kill-server command comes with a few important considerations:
1. Killing the server will temporarily disconnect all currently connected ADB sessions and devices from your host machine.
2. Subsequent adb commands will automatically restart the server, which is usually the desired behavior for troubleshooting.
3. This command only affects the ADB server running on your host machine, not the adbd daemon running on the Android device or emulator itself.
4. Ensure you have the necessary permissions to kill processes on your system.

You should use adb-kill-server primarily for troubleshooting ADB-related issues. Common scenarios include:
1. When adb devices shows no devices, or devices are listed as 'offline' incorrectly.
2. If you encounter 'ADB server didn't start' or 'cannot connect to daemon' errors.
3. After updating your Android SDK tools or ADB version.
4. To resolve unexpected disconnections or communication failures with devices.
5. When switching between different ADB versions or encountering port conflicts.

It's often followed by another adb command (like adb devices) to implicitly restart the server.

The Android Debug Bridge (ADB) has been an integral part of the Android SDK since its inception, providing developers with a versatile command-line tool for interacting with Android devices. The kill-server subcommand, along with start-server and the implicit server management by other adb commands, has been a core utility for many years. Its development reflects the need for robust control over the communication bridge between development environments and target devices, ensuring a reliable mechanism to reset or troubleshoot the ADB environment when necessary. It has remained largely consistent in its functionality due to its foundational role.

adb(1), adb start-server, adb devices