Thinking of selling your Android, trading it in, or donating your phone to charity but there is important or private information that you don’t want anyone else to have access to? Here are a few tips that you can use which can help keep your personal and confidential data private once your cell phone is no longer in your possession.
Is a hard reset enough?
Performing a reset by choosing the Wipe data/factory reset option through the Android System Recovery feature or choosing to Factory data reset through the Android Settings are two of the most common methods that people use to try and scrub all of the information from their Android cell phone or Android device.
But does performing a hard reset actually guarantee that your information is gone for good? After all what would be the purpose of all those warning messages asking you to confirm the reset if it didn’t actually delete all of the user data from the device?
Whether it’s a picture from your camera, a screenshot, an image, a file, a note, a text message, app data, your contacts, email accounts, whatever information that may have been added to the phone while using it a factory reset should erase that information from the phone and prevent access to it. Side Note: If you want to learn more about hard resets then you might find this Hard Reset FAQs informative and helpful.
For the most part, a hard reset should be more than enough to wipe the user data from your smartphone and prevent the recipient of your cell phone from having access to that information. If however you need to make absolutely sure that your information is unattainable after you have given up ownership to it then here are some methods you can use to take that extra precaution.
Data recovery programs
Can someone use a data recovery program in order to find or locate deleted files even after a factory data reset? Yes, No, perhaps, yeah, maybe, it depends.
How a data recovery program works
Before we get into some preventative measures that you can take let me briefly talk about HOW someone MIGHT be able to TRY and recover or find deleted or erased files, folders, or other information that may have been stored on an Android before that data was erased or before the cell phone had been reset.
This is going to be a very brief and basic description but just like with a computer or other electronic device that can store information to a hard drive, when you “erase” or “delete” something from a device like a smartphone it does not necessarily remove it from the drive but instead it removes the path to access that piece of information and then allows that space on the drive to become available again allowing it to be overridden if the space is needed later for other data. Erasing this path or pointer file makes the “deleted” info invisible to the Operating System and eventually the hard drive will write new data over the area where the old file is located. The chances of fully recovering data that has been erased from an Android diminishes the longer you wait as the “deleted” files are likely to be overridden by other newer information that gets saved to the drive.
So what a file recovery program actually does is it goes through the hard drive looking for these types of files and data and then it tries to make it available again in order to restore it to your smartphone or computer etc.
So it is unlikely… but possible
Will the new owner of your cell phone stumble upon your deleted/erased/formatted information if you perform a hard reset before giving it to them? Nope. Not under normal circumstances they won’t.
But could the new owner try to use specialized software in order to recover preexisting files, data, and other information from the hard drive? Technically, yes they could. There is no telling what they might be able to recover, if anything but it is technically possible. So if you have sensitive information on your device that you do not want anyone to recover under any circumstances then here is what you can do to stop it from happening.
How you can thwart a data recovery program
Encrypt your data
This is probably the BEST way to prevent someone from accessing your data after a reset or after the fact because even if they do manage to somehow recover the deleted information it won’t matter because the information will still be encrypted and the person won’t be able to open it or view it.
Disclaimer!! Before encrypting your Android there are a few things you should consider.
- Data Encryption is a One-Way Street – once your Android is encrypted there is no turning back and you will have to re-enter the encryption key, PIN or Password every time you want to use your device. The only way to disable or remove the encryption is by resetting the phone and starting over again from scratch. Side Note: If you encrypt your Android and then decide that you no longer want your phone encrypted some cell phones may allow you to decrypt your information again. For example: an encrypted Samsung Galaxy S4 has a “Decrypt device” feature located within its Security Settings.
- Performance Speed – since your cell phone has to decrypt your information it requires more system recourses and the result is typically a loss in performance speed.
- Backup First – if you have upgraded or purchased another cell phone then don’t forget to backup your information to your new cell phone before encrypting or resetting the old one. It can help with the speed of things and can certainly make things smoother when transitioning to another smartphone.
- Encrypt with a fully charged battery – depending on how much information that you have on your smartphone the encryption process can take a while to complete. Often an hour or more… Your phone might not even let you try to encrypt it if it doesn’t have at least an 80% charge on the battery. I recommend that you charge your cell phones battery to full and then have it plugged into a charger while it’s encrypting.
How to Encrypt your Android
The exact steps that you will need to take to encrypt your specific make and model of Android may differ from cell phone to cell phone but you should be able to locate this feature in your smartphones Settings under the Security option.
Once you open up your Security settings you should be presented with an “Encrypt device” and an “Encrypt external SD card” option. Since you want to encrypt your cell phone you are going to want to choose the “Encrypt device” option.
As mentioned above you might need to plug your phone into a charger and then verify that you have a minimum of 80% charge on your battery. You will also need to “Set an unlock password of at least 6 characters, containing at least 1 number” this is the PIN/Password you will need to use to unlock and decrypt your information when you want to use your cell phone.
Once your Android is done encrypting then double check to makes sure you don’t need anything from it before resetting it. After you have confirmed that you won’t lose anything of importance go ahead and perform the hard reset. Once the hard reset is complete your phone will be ready for its new owner and your personal, private or confidential information will be secured and inaccessible.
Overwrite the previous information
I mentioned briefly that after information has been erased the data may still remain on the drive until it is overwritten by something else. Well after reformatting you could do just that. You can fill your phones memory to the brink with worthless or irrelevant information replacing all of the previous data that may have remained. Then if someone does attempt to recover anything all they will be able to find is the irrelevant data that you put on the phone before the reset.
It doesn’t really matter what information you end up choosing to use in order to overwrite the previous data but it might save you some time if you use large files, such as movies or videos, so that your memory can fill up quicker. But it really doesn’t matter what you use. If you wanted you could turn your camera settings to the max resolution and just take pictures until your memory fills up. You could even transfer files from a PC to your phone in order to fill it up.
Just remember to make sure that the information is saving to your devices internal storage and not its external storage like a memory card.
Use an App
I think that the techniques listed above are going to be the best options available when trying to secure the information on your cell phone and do not typically suggest downloading or using applications, especially third party applications, for such tasks BUT for the sake of being thorough I thought that I would mention this method as well.
There are some applications that you can download from the Google Play Store that are designed to destroy files permanently; typically by overwriting the information with random data. In essence completing the task mentioned above.
To find one of these applications you can visit the Play Store and do a search for “File shredder” which will give you many different applications to choose from. Just make sure to do some browsing and read some ratings and reviews so that you can try to locate the best one available.
That is how you can permanently erase everything from an Android
So a quick recap on how to permanently delete and remove the files, folders, and other private or confidential information from your Android smartphone or Android device.
- Hard reset – a factory data reset and standard data wipe should be more than enough for the average Android user and in the majority of circumstances this feature should also be sufficient enough to keep your private or confidential information from being accessed by whoever ends up receiving your cell phone. For the most part a person isn’t going to even consider trying to recover your information or even have the means to do so. Usually they are just happy to receive and own a cool and working smartphone.
- Encrypt and then reset – if you use your Android for work or business however or you have private or confidential information on your device and you don’t even want to take the chance of someone trying to recover it then the best thing to do is encrypt your entire phone and then hard reset it. That way if someone does end up trying to recover something the data will still be encrypted and useless to them.
- Reset and override – after the reset (or even the encryption and reset) you can then fill up your cell phones memory with random or insignificant data to override anything important that might be lingering on your phones memory.
- Use an app – There are some apps on the Play Store specifically designed to make data on your Android unrecoverable and you should be able to locate and choose the best one of these apps by performing a search for “File Shredder” or “Data Wipe” on the Android Play Store.
Thank you for reading and enjoy
I hope that you found this guide informative and a beneficial resource concerning the securing of information on your android smartphone.
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Thanks for reading, enjoy the knowledge that your information is nice, safe, and secured and I hope you have a wonderful day.
6 thoughts on “How to properly delete everything from your Android phone”
I encrypted my Xperia M2
Hi,
I encrypted my Xperia M2 and I do not like it. I did factory reset but still the same. The encryption is still there.
Any solution back to the new phone setting?
Thank you.
Decrypting an Encrypted Sony Xperia M2
Hi David,
Once a piece of data on your Android is encrypted it’s often going to remain encrypted. Some phones, like my Samsung Galaxy S4, will allow you to decrypt all of the encrypted information stored to the device but if this feature is not available then a hard reset should do the trick.
When you say that you performed a factory reset and your encryption is still there it leads me to believe that the hard reset did not complete successfully; which I have seen happen before.
I suggest performing another reset for good measure. If that doesn’t work then you should consider utilizing the backup and restore feature of Sony’s PC Companion or even the official Sony Flash tool as the Xperia M2 is one of the phones that can make use of that tool.
I hope that helps David. If you have any more questions or hit any snags than just let me know and I’ll see what I can do to try and help.
It said “Backup fail”
It said “Backup fail”. The phone is encrypted” in PC Companion. I do not dare the flash as not an expert. Just leave the way it is at this moment.
Thank you for the ideas. Cheers.
Files overwritten
I’m going to ask this the best way I know how? 🙂 is a conversation with one contact considered a file? and if that conversation is deleted and then discontinued, will this file be just as likely to be overwritten by other data while the phone is in use? or will it not likely be overwritten because it is recognized as one file left alone and not overwritten by a new conversation?
Electronic filing systems and telephone conversations…
Hello Sarah,
I am not sure I understand what you are asking….
I suppose that when you receive a call, or make a call your phone will keep a record of that in your phones call log which I suppose could be considered a file? The only thing out of the box that I can think of that can record conversations and create a file for that conversation is your voice mail. But that is a little inaccurate as well because voice mails don’t get stored on your cell phone they get stored by your wireless service provider…
Speaking of wireless service providers… remember that your service provider has a record of your conversations stored in their system. They can see what telephone numbers that you have spoken to, who called who, when the call was made, how long that call lasted, etc. All this information gets stored on your wireless service providers end. You are after all using their towers and equipment for your service.
I’m not sure if that helps to answer your question Sarah, but if not then please don’t hesitated to post a reply to this comment with a little more details about what you are trying to find out and I will do what I can to try to provide an answer. The more information you can provide the better answer I will likely be able to give you.
Hope to hear back from your soon.
Overwrite
Hello, my question was more about a text message file that holds a conversation, not voice mail. I am understanding that one file equals all text messages under 1 contact number. Is this wrong?
So lets say text messages under 1 contact number happened between date x and y (4 months and then stopped, a very short time). Would this file be most likely written over with new data , just like any other,or most likely left alone and easier to recover because conversation stopped with contact number (file). I am trying my best to explain, but I don’t know if I have it even close.
I’m not even sure how long it takes to overwrite data in an active droid phone, if its years or months or days.
Thank you for your time.