ADB Reboot: Recovery, Bootloader, Fastboot and Download Mode

With USB debugging on, adb reboot restarts your phone normally, and adding a mode such as recovery, bootloader, fastboot or download sends it straight into that special boot mode without pressing any hardware buttons. This is handy when the key combination is awkward, the buttons are broken, or you are scripting a workflow. You can also trigger the same actions from a Chromium browser with ADBKit.

Warning: Recovery, bootloader and download modes exist for system-level work. Selecting the wrong option there can erase data or leave the phone unable to boot. If you are unsure what an on-screen option does, leave it alone and back out.

The reboot commands at a glance

Each command assumes the device shows as device in adb devices:

The exact set that works depends on the manufacturer and Android version. If a mode is not supported, the phone simply reboots normally or ignores the request.

What each mode is for

Recovery

Recovery is a small separate system used for maintenance. The stock recovery typically offers options such as rebooting, applying an update from ADB, and wiping data (factory reset). Custom recoveries add more tools. Open it with:

adb reboot recovery

On some phones you will see a "No command" screen with an Android logo. Holding the power button and pressing volume up usually reveals the menu, though the combination varies by device.

Bootloader (fastboot mode)

The bootloader is the first software that runs at startup. In its fastboot mode, a computer can talk to the phone with the fastboot tool, which is how factory images are flashed and how the bootloader is locked or unlocked. Enter it with:

adb reboot bootloader

Note that adb does not work in this mode; the device now answers to fastboot commands instead, such as fastboot devices.

Fastbootd (userspace fastboot)

Many newer devices use dynamic partitions, where system partitions live inside a single logical container. Flashing those partitions is handled by fastbootd, a fastboot implementation that runs from the recovery image. Enter it with:

adb reboot fastboot

Download mode on Samsung

Samsung phones use their own download mode, which works with tools such as Odin to install firmware. Enter it with:

adb reboot download

The phone shows a warning screen asking you to confirm before it continues.

Risks to know about

• Unlocking the bootloader usually wipes all data. Phones are designed to erase user data when the bootloader is unlocked, so back up first. Some manufacturers also void the warranty or disable certain features.
• Flashing the wrong image can brick a device. Use only firmware made for your exact model and region.
• Wipe options are permanent. Factory reset in recovery removes your apps, accounts and files.

This article does not cover flashing or unlocking, because the steps are device-specific and mistakes are costly. Follow your manufacturer's official documentation for those tasks.

How to get back to normal boot

If you land in a mode you did not intend, you can usually leave it without changing anything:

• Recovery: choose Reboot system now from the menu.
• Bootloader or fastbootd: run fastboot reboot from your computer, or select the start or reboot option on screen.
• Samsung download mode: choose the option to cancel on the warning screen, or hold the power and volume down buttons for several seconds until the phone restarts.
• Anything unresponsive: hold the power button for about 10 to 20 seconds to force a restart; the exact duration varies.

Reboot and power off from ADBKit

ADBKit puts these actions in the workspace so you do not need platform-tools. Connect your phone over USB (enable USB debugging, click Connect device, pick the phone in the browser's USB window, and tap Allow on the phone), then use the power actions:

• Reboot and Power off
• Recovery
• Bootloader (fastboot) and fastbootd
• Samsung download mode

Each one asks for confirmation first, so a stray click cannot send the phone into a boot mode. ADBKit runs in Chromium-based desktop browsers such as Chrome and Edge over HTTPS, and nothing from your device is sent to an ADBKit server. If the connection fails, only one program can hold the USB connection at a time, so close Android Studio or scrcpy, or run adb kill-server.

For other everyday commands, see the ADB commands cheat sheet, and if you have not enabled debugging yet, start with how to enable USB debugging on Android.