When you delete a file on your Android device, it may seem like the file is gone forever. However, that is often not the case. Deleted files can remain on your device’s storage and be recovered later. So are deleted files really deleted on Android? Let’s take a closer look.
What happens when you delete a file on Android?
When you delete a file on an Android device, the file is not immediately erased from the storage. Instead, the operating system simply marks the space occupied by the file as available for new data. The actual file remains on the device’s storage until that space is overwritten by new files.
This is done for performance reasons. Erasing files immediately would take a long time and use up processing power. Marking files as deleted and overwriting that space later is much faster. But it means deleted files remain recoverable until they get overwritten.
Can you recover deleted files on Android?
Because the deleted data remains on the storage, it is often possible to recover deleted files on Android devices. There are a few ways to try recovering deleted data:
- Android data recovery apps – There are various third-party apps that can scan your device’s storage and recover deleted files.
- Digging in backups – If you have a backup of your device from before the file was deleted, you may be able to retrieve the deleted file from the backup.
- Plugging into a computer – You may be able to mount your Android device’s storage on a computer and use data recovery software to restore deleted files.
The chances of recovering a deleted file depend on how long ago it was deleted and whether any new data has overwritten the space where it was stored. The sooner you try to recover a deleted file, the better chance you have of getting it back.
When are deleted files really gone from Android devices?
Deleted Android files are only really gone when their storage space has been overwritten by new data. As long as the space is marked as empty, the deleted data remains and could potentially be recovered.
So a deleted file is essentially still there until one of the following happens:
- You directly overwrite the file’s disk space by saving a new file there.
- The operating system saves new application data to that space.
- A disk optimization or cleaning utility actively wipes the empty space.
As soon as new data occupies the same physical space, the deleted file is truly gone for good.
How to securely delete files on Android
If you want to make sure a file is completely erased from your Android device so that it cannot be recovered, you need to overwrite the data before deleting. Here are a couple methods to securely delete files:
- Use a file shredder app – File shredding apps will overwrite a file’s disk space before deleting it to prevent recovery.
- Encrypt the device’s storage – Enabling encryption on your Android device will overwrite all existing files with encrypted data.
- Wipe the storage – Performing a factory reset or wiping the storage will overwrite all user data making files unrecoverable.
Keep in mind that root access is required to securely erase specific files on Android. Without root, you can only overwrite all user data by wiping the storage.
Other factors that affect file deletion
In addition to direct overwriting of data, there are some other factors that can impact whether deleted files can be recovered from an Android device:
- Device encryption – Enabling encryption on your Android device will causes all existing files to be encrypted in place. An encrypted file that is deleted cannot be recovered without the proper decryption key.
- Trim command – This feature lets the operating system notify the storage hardware which blocks of data are no longer in use and can be wiped internally. This makes data unrecoverable.
- Wear leveling – Flash storage on Android devices use wear leveling algorithms that actively re-write data to different physical locations. This can overwrite deleted data over time.
Recovering deleted files from external SD card
If files were deleted from an external SD card on your Android device, the chance of recovery is higher compared to internal storage. This is because:
- SD cards typically do not use trim, wear leveling or other data rewriting techniques as aggressively.
- Encrypted storage is often limited to only internal storage, leaving external SD card data unencrypted.
- Users often remove the SD card before wiping their device, preserving the deleted data.
So as long as the SD card was not formatted after the file was deleted, recovery software should be able to restore deleted files from external storage in many cases.
Conclusions
To summarize the key points:
- Deleted files are not immediately erased from Android devices, just marked as empty space.
- It is often possible to recover recently deleted files using data recovery apps or methods.
- Deleted files are truly gone once their storage space is overwritten by new data.
- You can securely delete Android files by overwriting them before deleting.
- Factors like encryption, trim and wear leveling can affect recoverability.
- Deleted files from external SD cards have a higher chance of being recovered.
So in general, while deleted files are not necessarily gone forever on Android, they can become permanently irretrievable over time. To ensure sensitive files cannot be recovered, they need to be securely overwritten or the storage encrypted.
Frequently Asked Questions
Can deleted files be recovered from the trash or recycle bin?
Android does not use a recycle bin or trash system for deleted files. Any file you delete is immediately marked as empty space, so there is no trash location that stores deleted files. However, those files remain recoverable from the storage until overwritten.
What happens if I delete files from internal phone storage vs SD card?
Deleted files from both internal storage and external SD cards remain recoverable until their storage space is reused. However, SD cards are less likely to overwrite data quickly due to less aggressive wear leveling and trim support. So deleted SD card files have a higher chance of being recoverable.
Can factory resetting an Android device erase deleted files?
Yes, performing a factory reset or wiping data will overwrite all user data with blank space. This will render all previously deleted files unrecoverable.
Is data on encrypted Android devices unrecoverable if deleted?
Yes, enabling encryption on an Android device will overwrite all existing files with encrypted data. Any deleted encrypted file cannot be recovered later without the encryption key, which is erased on factory reset.
Are deleted files recoverable after an Android update?
Android updates do not generally overwrite user data, so deleted files remain recoverable after an update. The exception is a major Android OS version update, which may perform a quasi-factory reset that erases user data.
Can you recover permanently deleted files from Android?
If a file was securely and permanently deleted by overwriting the data before deletion, then no it cannot ever be recovered by any means. True permanent deletion requires overwriting data, encryption or physical destruction of the storage device.
Useful Resources
Here are some useful resources for learning more about recovering deleted files on Android:
- How to recover deleted files on Android – Android Authority guide
- Undelete Android Data Recovery – Whitepaper from UFONet
- NIST Guidelines for Media Sanitization – Data deletion guidance from National Institute of Standards and Technology
Recovering deleted files is possible in many cases if the data was not securely overwritten before deletion. With the right tools and techniques, undelete tools can salvage deleted files from Android devices. But overwritten and encrypted data is generally unrecoverable. Carefully consider whether to enable encryption or utilize file shredding apps if truly permanent deletion is required.
Example Data Table
Here is an example data table comparing different Android file deletion and recovery scenarios:
| Scenario | File Recovery Possible? |
|---|---|
| File deleted from internal storage 5 minutes ago | Yes, high chance of recovery |
| File deleted from encrypted storage | No, encryption makes recovery impossible |
| Deleted file overwritten by new data | No, overwritten data is unrecoverable |
| File deleted after factory reset | No, reset erases all user data |
| Deleted file from external SD card | Yes, higher chance of SD card recovery |
This table illustrates how the chances of recovery depend on encryption, overwriting and the storage type that the file was deleted from. This gives an overview of recoverability for common Android file deletion scenarios.
Summary
In summary, deleted files are not necessarily gone forever on Android devices. Recovery is possible in many cases if the file was recently deleted and no new data has overwritten the space it occupied. However, Android does employ techniques like encryption, trim commands and wear leveling that can render deleted files unrecoverable over time. To maximize recoverability when desired, quickly attempt file restoration before the storage space is reused. For sensitive data that should be securely erased, utilize encryption and file shredding techniques.