[golfvswag (OP)]

People are now changing their smartphone more frequently and most of them prepare selling the old one. I am the one too. I have an old LG G3 and bought a new S8. My question is how to securely delete all data on G3?

What is your thought on this?

[chris]

Does a factory restart not suffice? I think that wipes everything and reinstalls the OS from an immutable solid-state copy, so you get back a "clean" device. You can also remove the SD card and do a wipe on that using your laptop. That should be adequate to ensure that no data is given away with the device.

When you dispose of the device you'll also be removing the sim of course, which is the only other storage on there.

[RD]

Does a factory restart not suffice?

The factory reset doesn't overwrite the user data : it would still be recoverable by geeky types.

[ Prediction : another 1st time poster will be pushing software to do that in this thread shortly ].

[chris]

The factory reset doesn't overwrite the user data : it would still be recoverable by geeky types.

Gosh, I thought it did do a genuine over-write. That's quite a concern.

[ Prediction : another 1st time poster will be pushing software to do that in this thread shortly ].

Yes, that thought had occurred to me; which is why I am keeping a close eye on this thread for newbies that conveniently pop up with a link to a solution...

[SeanB]

Simplest is to delete all the user data then fill up the file system with random data ( video of a Rickroll will do, just copy it enough times to fill the file system usable space), then delete them all, do a factory reset and fill it up again and delete, then another factory reset. Then update the firmware ( or put it in bootloader mode and force reload the current firmware), and this should get almost all the data on the phone to a unusable state. Some will persist ( because it is in areas not normally readable by the filesystem, like the reallocated sectors in the flash file system, but there are hard to get to short of knowing the phone memory map, not the one the filesystem shows but the one it really uses) but it will be really hard to use random bytes for much.

SD card siply buy a new one, transfer the data across and put the old one in the drawer as backup, or use the method I use for faulty cards, which involves a 14lb hammer, called "Gentle Persuasion" and a cast steel rail slipper. Guaranteed data erasure there.

If you really want secure erasure you will need to put the phone (sans battery) through an industrial shredder, and after that roast it in a kiln to 1000C to destroy the data, as used in the 3 letter agencies to erase all the data they want to really make sure is deleted.

However for most users the first method at least preserves most of the phone value.

[golfvswag (OP)]

@SeanB, the data is impossible to be recovered according to the details you suggested in method 1. However, there are two main issues:
1. You would miss something as it is hard to find all user data
2. Take much longer time if the internal storage is large.

Safewiper Android Eraser is a suggestion of my friend. And all data being wiped clean after testing with pro data recovery apps.

[Tahensty]

People are now changing their smartphone more frequently and most of them prepare selling the old one. I am the one too. I have an old LG G3 and bought a new S8. My question is how to securely delete all data on G3?

What is your thought on this?

If you have some sensitive information in your Android phone,  you must first wipe your Android before selling.  Don't just rely on factory reset due to it can't 100% wipe data on Android.

I recommend using A RELIABLE PRODUCT to wipe everything on Android phone, then perform factory reset. You can try safewiper for Android.

[chris]

I recommend using A RELIABLE PRODUCT to wipe everything on Android phone, then perform factory reset.

[ Prediction : another 1st time poster will be pushing software to do that in this thread shortly ].

Ah, right on cue, we wondered when you'd turn up with the magic solution to your earlier question... Well predicted @RD - you must be a mind reader...

[peterwu]

People are now changing their smartphone more frequently and most of them prepare selling the old one. I am the one too. I have an old LG G3 and bought a new S8. My question is how to securely delete all data on G3?

What is your thought on this?

If you have some sensitive information in your Android phone,  you must first wipe your Android before selling.  Don't just rely on factory reset due to it can't 100% wipe data on Android.

I recommend using A RELIABLE PRODUCT to wipe everything on Android phone, then perform factory reset.

what software can wipe Android phone completely?  I personally used safewiper for Android to wipe my phone, it works find but not free.

[Zer0]

Isn't there a way to do this, wipe without using any software products/programs ?   📲

Doesn't first encrypting all data on the mobile/cell phone n then completely deleting it help ?   📵

[mrrobin]

I have an issue with my android that is, I can't transfer my contacts to my new iPhone. Is there any way to transfer them from android to iPhone? Please suggest me if possible.

[Zer0]

Copying all contacts from the android phone/cell memory to sim card, n then removing sim n inserting it in an iPhone n copying all sim contacts to phone/cell, doesn't this procedure work ? 📱➡🎴📲

Or if the old android or new iPhone does not require a sim card, then can't one use a SD card n follow a similar transfer technique/procedure ? 💾❓

[SeanB]

Simplest is to backup to Google and then log into drive on the iPhone, and sync the data. At least that is what I have read, Android generally comes with a need for a Google account.

[RubyPerkins]

Thanks for the help. I was also facing the same issue with my android phone.

[sophiewilson0191]

If you can flash it, all files will be new.
better format is several times.

[dujiacun]

The right way to wipe an Android phone is using Android data eraser program. With its help, we can wipe personal data from an Android phone, such as contacts, cache fils, junk files, text messages, videos, photos, music and so on.

[bikasgaur]

The most straight-forward way is to factory reset your android device. Those "geek types" guys who promise can recover those deleted files using those magical software found online is just a big lie. Plus you are not Edward Snowden so you can chill ;-)

[Zer0]

Factory Reset does NOT delete all Data on an Android Device. 👊

" Chris - When someone defines their phone as wiped, does that mean they've sort of gone into the settings because there's a button you can sort of select on the phone that says, reset to factory, isn't it? That it sort of resets it to how the phone apparently was when it came out of the box. Is that actually what happens?

Laurent - Most people actually use this setting on the phone. And that's what the vendors suggest you to do before you sell your phones. It doesn't always delete the data and why this data is not properly deleted, you first have to understand how the data is stored on your phones. So, phones basically store the data the same way a library would store books. So essentially, you have books on your shelf and every time you want to access a book, you have to look up its location in a search index table. Now, some phones, when they wipe the data, they will actually delete both this index table and remove the books from the shelves. But some phones will actually only remove the index table. So, it appears to you as if your data has vanished, but if you look directly at the shelf, the data is still present. "

" Chris - So, what can someone do about this? If you're someone who's about to flog an old phone or give it away to your kids or something, what can you do to make sure you're not a victim of something like this happening?

Laurent - Okay, so that's a difficult question because as I said, all phones are different and it depends on the model. But there are some steps that we can take to try to improve the situations. One of the things you can do before you resell your phone is to enable the encryption option in your settings. This basically scrambles your data to make it difficult to retrieve by someone. This technique essentially is often as reliable as the strength of your passphrase. So you're better off with a really long passphrase. Once you've enabled this option, you restart your phone, you ask for the passphrase and you can wipe your phone. For multimedia files, it's a little bit different especially on the android platform. So, if you actually want to get rid of this data, you have various possibilities, none of them are fully reliable but they will improve the situation. So, one of them is to use an external memory card to save your pictures instead of the default one on the phone. A second option is to connect your phone to your computer via a USB cable and delete manually the files on your phone and copy large files on the phone into your...

Chris - Basically, just fill up your phone with stuff and it's a bit like shoving new stuff onto the shelves of your library. It's going to push out all the old stuff so the fingerprint of it being there is gone. So, even though you're giving some data away, it's still stuff you don't care about because it's just random rubbish.

Laurent - Exactly. So, as I said, this is not fully reliable but this will help. Another way you can do this is also by trying to record a really large video until some of the memory is full. "

https://www.thenakedscientists.com/articles/interviews/your-phone-wiped-after-factory-reset

Thanks & Credits - Laurent Simon. (University of Cambridge) 👍

[JaneMiller]

I think it will be better and safer if you erase all data on your phone and factory reset it. After that, please remember to use new data to cover the old data which have the possibility to be restored. For example, you can take numbers of new random pictures. And then wipe your phone again.

[Galaser]

I think it will be better and safer if you erase all data on your phone and factory reset it. After that, please remember to use new data to cover the old data which have the possibility to be restored. For example, you can take numbers of new random pictures. And then wipe your phone again.

Generally speaking,it would take 15 working days for the data to be fully covered.