Fastboot Flashing Guide - ADB, And Fastboot Commands

Guide 2 min read Updated: Dec 17, 2025

Fastboot Flashing Guide

Use ADB & Fastboot to unlock bootloader and flash images safely

Important

Bootloader unlock wipes all data. Flashing wrong images can brick the device. Backup first and ensure battery > 60%.

Prerequisites

Android Platform-Tools (ADB & Fastboot)
USB drivers for your device
Original USB cable
Firmware images (boot.img, recovery.img, system.img, vendor.img, etc.)

Step 1: Enable OEM Unlock & USB Debugging

Open Settings → About phone → tap Build number 7 times to enable Developer options
Settings → Developer options → enable OEM unlocking and USB debugging

Step 2: Reboot to Bootloader (Fastboot)

adb devices
adb reboot bootloader

Step 3: Unlock Bootloader (if locked)

Warning: This will factory reset the device.

fastboot flashing unlock
# Some brands use:
# fastboot oem unlock
# Confirm on device if prompted

Step 4: Flash Images

Use only images matching your exact model and Android version.

# Example: flash boot, vendor, and system
fastboot flash boot boot.img
fastboot flash vendor vendor.img
fastboot flash system system.img

# Optionally flash recovery
fastboot flash recovery recovery.img

Step 5: Reboot

fastboot reboot

Troubleshooting

Device not detected: Reinstall drivers, use USB 2.0 port, try different cable
Flashing denied (locked): Unlock bootloader first
Invalid sparse file: Use correct image set for your build
Bootloop after flash: Wipe data/cache from recovery; ensure images match device variant

Tip: Some vendors require an unlock token (e.g., Motorola) or OEM authorization (e.g., Xiaomi). Follow brand‑specific instructions.

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