Think zillions of times before you sell your phone or give your phone to any repair shop or even to any elite trustable customer service. They can get your data recover even after you have done factory reset and delete your data.

Secrets

Our smartphones are privy to some of our most important secrets. Sensitive business emails, financial details, contact information, and perhaps even very personal photos (first what are such stuff doing on your phone) are not things you want falling into the wrong hands.

Remember

Performing a factory reset nothing more than just a good idea. It certainly not enough that data has been removed.

Remember your data including your personal photos, Google searches, emails, text messages, and contact details can be recovered even after you factory reset, as your data is still not overwritten.

What to do

Follow below four steps to wipe your Android phone, to make sure data is properly gone. (Similar steps can be followed for iPhone)

Step 1: Encrypt your data

The first step is to encrypt your data (If it is not already encrypted or using old Android versions). This option is available built into Android (may not enabled by default). Encryption requires you to enter a PIN or password every time you turn your phone on.

• Fully charge your phone or keep it plugged into the charger while this process is running, because it can take several hours depending on how much data you have.

  Note: The exact method may be differ slightly from phone to phone, however it will generally be like below

• Go to Settings > Security > Encrypt phone.
  
  
• Or Go to Settings > Security & location > Advanced > Encryption & credentials and select “Encrypt Phone”
  
  
• Or on Samsung Galaxy, Go to Settings > Lock screen & security > Protect encrypted data
  
  

Step 2: Factory Reset

Make sure you have already setup your new phone or that you have anything you want to keep backed up before you do this because it will wipe everything. Once phone has reset, there’s no going easy back. The steps are similar for most Android devices, but some manufacturers like to be different.

• Go to Settings > Select System > Advanced > Reset options > Select “Reset phone.”

  Note: If you have a PIN or some other security setup, you’ll be asked to enter it. You’ll get another screen asking if you’re sure this is what you want to do. Are you sure? Then hit the “Erase everything” button.

• Or On a Samsung Galaxy, Go to Settings > General Management > Reset > Factory data reset and then tap Reset device.
  
  
• Or On a Huawei phone, go to Settings > System > Reset > Factory data reset and then tap Reset Phone.
  
  
• Or On a Google Pixel, it’s Settings > System > Advanced > Reset options > Erase all data (factory reset) and then tap Reset phone.
  
  

Step 3: Overwriting with junk data

Now final step is to be absolutely certain, by overwriting the encrypted data with junk data and then perform another last factory reset as done in step 2.

• Simply load a bunch of dummy data onto your phone until the storage is full. A few large movies videos should do the trick.
  
  
• Or Open your camera and keep recording video for hours long (like record open sky or charming birds or beautiful garden) till storage full.
  
  
• Or you can also get an app to do it for you. Install any of these or similar app from Play Store, such as Secure Erase with iShredder 6 or Shreddit.  
  

Note: Do not use your personal Gmail / Google account, instead create new dummy temporary google account to download these app to overwrite storage, as by using or connecting your actual google account you may accidentally restore data back again on device from Google drive.

Step 4: Final Factory Reset

Once above three steps completed and the data is overwritten by these app or video camera recording or you fill up storage with movies, perform another last factory reset as done in step 2. That’s how you completely wipe your Android phone.


Note: Never sell your SD Cards and Hard Drives, break into pieces and throw it away in garbage, even if they are not working or dead.