Custom ROMs 101: Things to do before and after flashing a custom ROM

BY Rajesh Pandey

Published 12 Mar 2014


Flashing a custom ROM is a pretty tedious process, especially for first timers and requires users to take a lot of cautionary steps just in case things go wrong. There are a lot of things you must keep in mind before you decide to install a custom ROM and even after you have installed it. Continue reading this post to find out what they are.


The first step to do before flashing a custom ROM is to make a backup of all your data present on the device, including the contents on the external SD card. It is also recommended that you create a “nandroid” backup of the stock ROM itself, which you can restore just in case things go wrong. To take a nandroid backup, your Android device must be rooted with a custom recovery installed. Simply reboot to the custom recovery installed and then select Backup to make a nandroid.

Double check the files

Make sure to double check that you have downloaded the ROM that is meant for your specific variant of the handset. Otherwise, at the time of installing the ROM, you will get an error or worse, end up bricking the handset.

Don’t forget to wipe

Don’t just boot into recovery and install a custom ROM — your device will have a high chance of getting stuck in a boot loop. You need to first wipe the /data partition, which contains all your installed apps. You can do this in your custom recovery by using the wipe data/factory reset option or by going into Wipe and swiping the arrow at the bottom to the right.

Install Google Apps

The majority of the AOSP-based custom ROMs like CyanogenMod or AOKP don’t come with the Google Play Suite of apps pre-installed. Make sure to install them manually by flashing the Google Apps package after you have installed the ROM. However, you should reboot the device after installing the custom ROM once before you flash the Google Apps package.

Let everything settle down

Don’t start judging a custom ROM’s performance right after it has booted. Wait for at least a few minutes to let everything settle down. If things still feel sluggish, reboot your device again. 

Check everything

Before you start setting up the device after flashing a new ROM, make sure to check that every piece of hardware is working including the Camera, GPS, Bluetooth and Wi-Fi. Even though the ROM page might not mention anything, there are chances that a critical piece of hardware is not working properly.

What are some things that you always check before installing a ROM? Drop in a comment and do let us know.