Re: Erase all content and settings on your iPhone, iPad Permanently
If you want to erase all of your iOS device, you can use its factory settings. You need to do the following steps.
1. Go to "Settings
2. Scroll down and tap General
3. Scroll down and tap Reset
4. Tap Erase All Content and Settings
5. Enter your passcode
6. Tap Erase iPhone".
Then you can erase data on iPhone
. Besides, you are supposed to back up all your iPhone data before you reset your iPhone.
In order to make sure that you wipe your iPhone data completely, you can use some data eraser apps to help you delete iPhone data permanently