What is a Factory Reset?
A factory reset refers to the process of restoring a device back to its default settings as it was when it originally left the factory. This resets the device to a clean slate and wipes all personal data, including photos, messages, downloaded apps, and account information (Definition of factory reset – Encyclopedia).
Essentially, a factory reset erases all user data from the device’s storage and returns it to its out-of-the-box configuration. This means removing any installed applications, saved files, configured settings, stored WiFi passwords, and more. It aims to make the device look and function as if it were brand new. Factory resets are commonly used when selling, returning, or troubleshooting issues with a device.
Data is Still There After Reset
When you perform a factory reset on a smartphone or other device, it does not actually erase the data. The reset simply marks the data as deleted and available to be overwritten by new data. But the original data still physically exists on the device’s storage until it gets overwritten (source: xdaforums.com).
Performing a factory reset essentially tells the operating system to forget about the data and allow it to be overwritten. But a reset alone does not actively wipe or overwrite the data itself. So traces of the original data may still reside on the device even after a reset, at least until new data saves over the storage space.
This means deleted photos, messages, files and other personal data could potentially be recovered after a factory reset if the storage space has not yet been reused. The data is not totally erased by the reset process itself. A factory reset alone does not completely obliterate data or make it unrecoverable.
Recovery is Possible
Data recovery after a factory reset is possible in many cases. Even though the reset deletes personal data from the device’s internal storage, it does not actually overwrite or permanently remove the data (Source). The files are simply marked as deleted and become inaccessible to the operating system. As long as new data has not yet overwritten the deleted data, recovery tools can locate and restore it.
There are many data recovery tools, both free and paid, that can effectively recover deleted files even after a factory reset. Some well-known tools include Recuva (Freeware), TestDisk (GNU General Public License), and MiniTool Partition Wizard (Freeware). These tools scan the device’s storage to find recoverable deleted data. The more quickly you run a recovery after the reset, before new data overwrites the deleted files, the more data you can restore (Source).
For those needing assistance, many companies specialize in professional phone data recovery services and have expertise in recovering data even from reset devices. However, these services can be expensive. The best approach is to avoid needing data recovery in the first place by regularly backing up your device data to the cloud or an external storage device.
Overwrite Deleted Data
Simply performing a factory reset is often not enough to prevent the recovery of deleted files. While a reset will delete user data and restore the device to its original settings, it does not actually overwrite the stored data (Source 1). The data still physically resides on the internal storage and can be recovered with specialized software.
To better protect your sensitive information before selling or disposing of a device, experts recommend manually deleting personal files and then filling the storage capacity with new dummy files, such as movies or music (Source 2). This overwrites the deleted data and makes it much more difficult for someone to recover afterward.
Simply deleting files does not overwrite them either, so it’s important to fill the storage with new files. You may also want to reformat the internal storage when factory resetting to overwrite previous file systems. While data recovery is still possible, manually overwriting your data first provides an extra layer of protection.
Use Encryption
Encrypting your device and SD card is critical for protecting your data. Encryption transforms your files into an unreadable format so they cannot be accessed if your device falls into the wrong hands. As the Iolo article explains, “Files Can Still Be Recovered After a Factory Reset” if encryption is not enabled beforehand.
When you perform a factory reset, it simply erases the encryption key needed to decrypt the data. The data itself remains on your device, though scrambled. So enabling encryption essentially makes your data unrecoverable after a reset, as detailed on AirDroid: “It is important to note that removing device encryption may also require a factory reset, which will erase all data on the device.”
Therefore, encrypt your Android device and memory cards before resetting to safeguard your personal information. A factory reset alone is not enough to prevent data recovery.
Be Cautious of Resale
When selling or donating a used device, it’s important to be aware of the risks of exposing personal data. Even after a factory reset, it may be possible for someone with the right tools to recover some data from the device’s internal storage (see https://www.comparitech.com/blog/vpn-privacy/wipe-android-phone-before-selling). A factory reset only removes data from the user-accessible storage, but does not completely overwrite all existing data on the device.
For this reason, if you have highly sensitive data on the device and cannot risk any exposure, it’s best to destroy the device physically rather than selling or donating it. This will ensure no data can be recovered. Options include removing and destroying the internal storage chip, or rendering the device inoperable. However, for most casual users, a factory reset is likely sufficient as long as no highly sensitive data was stored on the device (see https://www.reddit.com/r/cybersecurity_help/comments/15up678/is_selling_an_android_phone_really_not_safe/). Use your best judgment based on your personal data and risk tolerance.
Cloud Backups
Many people utilize cloud storage services like Google Drive, Dropbox, or iCloud to backup data from their devices. It’s important to understand that performing a factory reset does not delete files stored in these cloud accounts. The data remains accessible after the reset unless manually deleted.
If you plan to sell or dispose of your device, it is crucial to take additional steps to secure cloud data. First, change the passwords on any cloud accounts that were linked to the device. This prevents continued access in case login credentials were saved on the device. Additionally, manually delete sensitive files stored in cloud servers that you do not want the next user to access.
While a factory reset wipes data on the local device storage, performing a few extra cloud security steps is vital. This ensures your data does not fall into the wrong hands through existing cloud backups.
Sign Out of Accounts
A factory reset typically does not affect user accounts logged in on a device. Performing a reset while still logged into accounts like email, social media, and cloud storage could potentially allow access to those accounts through cached credentials even after the reset is complete (wired.com).
It is strongly recommended to ensure you sign out of all accounts on the device before performing a factory reset (support.google.com). This will revoke access to those accounts from the device and prevent any unauthorized access after the reset.
To sign out, go into your device settings and locate the accounts or users section. Tap through each account you are signed into and select “Sign out” or “Remove account.” Double check that you are fully signed out of every account before proceeding with the reset (wired.com).
Taking this important step will protect your accounts and personal data during and after the factory reset process. Don’t forget to sign back in on your newly reset device to restore access to your accounts.
Reset Doesn’t Affect Removable Media
When factory resetting a device, the reset only affects the internal storage and installed apps on the device itself. Any external or removable media like SD cards, external hard drives, or USB flash drives connected to the device will not be modified or wiped during the reset process.
As the USB Drive Factory Reset Tool site explains, resetting a device “does not affect any other storage media or devices connected to computer.” So if you have sensitive files saved on an external drive or removable media that was connected to the device, those files remain intact after a reset.
If you want to fully wipe any removable media that may contain sensitive data from the device, you will need to manually delete the files, reformat the external drive, or use a secure erase tool on those devices separately.
It’s important to be aware that factory resetting the device itself does not remove data from any external sources that may have copied or synced files from that device previously. So removable media needs to be handled with the same care as the device when trying to fully eliminate sensitive information.
Takeaways
Here are the key points to remember about data recovery after a factory reset:
– Performing a factory reset on your device does not completely erase all data. Deleted files can still be recovered using data recovery software.
– To prevent data from being restored after a reset, you need to take additional steps like encrypting your device, manually wiping the drive, or physically destroying the drive.
– Factory reset also does not affect files stored on external or removable media like SD cards or cloud storage. These need to be wiped separately.
– Sign out of accounts, remove SIM card, unlink cloud services before performing a reset to ensure no data remnants persist.
– Overall, a basic factory reset alone is not sufficient to fully prevent data recovery. Additional overwrite, encryption, and physical destruction techniques should be used.