How to Securely Erase Data From Your Phone

For most people, wiping their phone starts and ends with performing a simple factory reset process. And that’s usually fine for everyday users, but the truth is a basic factory reset isn’t always 100% secure. In recent years, phone manufacturers have made it increasingly difficult to access data that was supposedly erased during a factory reset, yet vulnerabilities still exist. 

So if you’re extra concerned about your data security and privacy, keep reading because this article will cover:

• The shortcomings of basic factory reset 
• How to securely erase data on your Android 
• How to securely erase data on your iPhone
• Tools for securely erasing data on your iPhone or Android 

Why a Factory Reset Isn’t Always Secure

Most people think that doing a factory reset completely erases all data from a phone before selling or recycling it, but that’s not technically true.

A factory reset removes access to your personal data and restores the phone to its original factory settings. On many modern phones, this process also includes re-encrypting storage and clearing user accounts. However, the underlying storage isn’t always fully overwritten.

A 2023 research study titled “Assessing data remnants in modern smartphones after factory reset” looked at Android devices running Android 11 and 12 and found the following:

• Parts of the encrypted user data can still be accessed in binary form even after a factory reset.

• Some partitions on the device aren’t fully wiped, meaning forensic tools can recover information about how the device was used.

This doesn’t mean that all of your data is easily recoverable. The study emphasizes that finding remnants on modern phones still requires advanced forensic tools and expertise, but it does show that factory resets alone aren’t a reliable way to completely eliminate all traces for someone with the right skills and tools.

Pre-Erase Essentials: What to Do Before Wiping Your Phone

Before learning how to factory reset your phone properly, there are a few crucial steps to take before wiping it clean.

• Back up important data to the cloud or external storage like an SD card, flash drive, etc.
• Sign out of accounts (Apple ID, Google Account, Samsung Account, etc.).
• Disable security features such as Find My iPhone (on iOS) and Find My Device (on Android), and OEM unlocking (if needed).
• Remove SIM and SD cards.

How to Securely Wipe Your iPhone or Android (Free and Paid Methods)

There are two ways to securely wipe your device whether you have an iPhone or Android. The first method is free but can be time and energy-consuming. The other method for securely wiping your phone is paid but generally takes less time.

How to Securely Wipe Your Phone: Free Method 

First, we start with the standard iPhone and Android factory reset.

For iPhone: Go to Settings > General > Transfer or Reset iPhone > Erase All Content and Settings.

For Android users wondering how to factory reset a Samsung phone or any Android device, go to: Settings > General management > Reset > Factory data reset. Note that the setting location may differ depending on your exact Android phone.

Now, instead of leaving the device as is, you’ll set it up again just enough for you to get into it, then fill up the storage with dummy data (large videos/files), and then factory reset the phone again. 

Don’t have dummy data? Then plug in your phone and start recording a video at the highest quality. At 60 fps, 128 GB of storage would last about 1 hour for 8K, 2 hours for 4K, 7 hours for 1080p, and 19 hours for 720p video. Actual times vary based on your camera settings, video complexity, and compression type.

You’ll also have to monitor your device, as recording video for long hours can cause it to overheat and stop recording.

Filling storage with videos/files can reduce recoverability, but on modern flash storage (UFS/eMMC) it may not overwrite the same storage blocks. So it’s a better than nothing method, not a guarantee.

How to Securely Wipe Your Phone: Paid Method

If you want to take the secure data erasure a step further, you can make use of professional data erasure tools. These tools are not free and might require a PC, but they have a high standard for secure erasure. Some even overwrite the data multiple times for added security. 

Professional Data Erasure Tools

To take secure erasure beyond a basic factory reset (and the dummy data overwrite method), you can use professional tools designed for secure, verifiable data sanitization. These tools often overwrite storage multiple times and can generate reports for compliance or audit purposes.

Here are some of the top options:

Bottom Line

Securely erasing data from your phone goes beyond a basic factory reset, but for people who don’t have the time or resources to go the extra step, it’s fine because even with a factory reset, a significant portion of your data is unrecoverable. If you do have the time or resources to go the extra step, please do so before selling, donating, or recycling your phone. The extra security might just be what prevents your sensitive data from being breached.

FAQs

Is a factory reset enough to delete all data?

No, in fact, a factory reset doesn’t delete all data. It simply makes old data (the data that was supposedly deleted) inaccessible for the most part.

Can data be recovered after a factory reset?

Yes, although it isn’t easily accessible, a portion of user data can still be recovered even on a factory-reset phone.

Are free data erasure apps safe?

In general, we wouldn’t recommend free data erasure apps without doing research on how they erase your data and how they ensure that your data is safe.