How to Backup Data Before Flashing a Custom ROM

One of the biggest advantages of Android devices is the freedom most manufacturers give you to go beyond the default operating system. You can personalize your phone by installing a specific custom ROM. However, this process does come with some risks — such as permanently erasing all your data or, in the worst-case scenario, bricking your phone (making it unusable unless you want to use it for spare parts).

Given these possibilities, it’s essential to take precautions by backing up your data before you begin. Doing so can make the entire flashing process much smoother and worry-free. In this guide, we’ll walk you through several easy methods to back up your data before flashing a custom ROM.

1. Backup via Google One

Since most Android devices are linked with Google, the easiest and most reliable way to back up your important data is by using Google One. This cloud service saves your data to your Google account. When you set up a new device, or after installing a new ROM, you’ll be able to restore your backed-up content easily.

The standard free plan gives you 15GB of cloud storage. If your files exceed this, you will need to purchase additional storage for your Google account.

Steps to Back Up Your Data via Google One

To back up your data with Google One:

1. Open the Google One app (you can get it from the Play Store; the link is below the image).
2. Tap “Set up” under Backup.
3. Press “Back up now” to start backing up your data.

2. Manually Backing up to a PC/Laptop

Cloud services like Google One make backing up convenient, but they’re not always perfect for every situation. Sometimes, not all files will be transferred, or your data may exceed the 15GB free limit. You might not want to spend money on more storage for a process that you only need temporarily.

The most reliable alternative is to manually back up your data to your PC. By doing this, you can be confident that everything—photos, videos, documents, and other files—are safely stored and accessible at any time after flashing the ROM.

Manual Backup, Manual Set-Up

The main drawback of manually copying your files to your PC is that, after installing your new ROM, your device will be as empty as brand new. You’ll need to copy your photos and files back by hand, and reinstall all your apps and settings—so this method does require extra work during setup.

3. Backup via Custom Recovery

If this is your first time installing a custom ROM, you’ll need to use a custom recovery tool. This is a special boot mode (separate from your regular Android system) that gives you a simple menu to do things like formatting partitions, installing new ROMs, or taking a full backup of your phone.

Most Custom Recoveries Support Backups

Popular custom recoveries like TWRP (Team Win Recovery Project), OFRP (Orange Fox Recovery Project), and PBRP (Pitch Black Recovery Project) all allow you to make a full backup of your device. So, if anything goes wrong while flashing a new ROM or updating a file (which is more common than you’d expect), you can easily restore everything back to normal.

Steps to Back Up Your Data via TWRP

To back up your data with TWRP, follow these steps:

1. Boot your phone into recovery mode.
2. Select “Backup“, then choose the data partitions you want to save.
3. Save the backup to external physical storage (such as your SD card or USB drive).

Once you’ve saved your backup externally, you can easily restore it later. Think of this like creating a System Restore point on your Android device. While these steps describe TWRP, the screenshot below shows where to find similar backup options in other custom recoveries. The overall process is very similar.