Before selling out your iPhone or handing it over for repair, always reset your phone's data and delete your accounts and content stored in it. You will have a peace of mind that data stored in it have been erased, and would never be misused. Of course, you need to make sure whether the data erased have been backed up to iCloud or iTunes or not. Backup the data and then reset the device.
You can factory reset your phone by just visiting Settings> General> Reset > Erase all content and settings.
But there are some steps you need to take first, we are going to provide you the simplest method to factory data reset of an iPhone.
How to Factory data reset an iPhone?
If you have made up your mind about erasing the stored data and return to the factory manufacturing settings, there are few steps to follow.
Backup the device first:
Though, there can be a separate article written on the topic, a shortened version needed here to explain.
I) you can use iCloud or iTunes to back up your iOS device
Go to settings > iCloud > Backup and ensure that the feature is enabled. From the option, you can see the last backup, and if you have just backed the data up, it is alright.
Factory reset the iPhone:
After backing up the data, you are going to factory reset your phone. That will completely wipe off your device and will make it see a factory manufacturing state. If you do not want to wipe off the data go back. If you want it to be done, go ahead.
Simply go to the Settings > General > Reset and choose to erase all content and settings.
Now, after providing the passcode you will have a warning box, tap this to yes.
It fills further ask an Apple ID password, provides that to confirm that it is you who wants to remove the settings.
You have restored your iPhone successfully; you see no content or settings are available.
There are others methods to factory reset the phone like using the iCloud or iTunes; this was the simplest method, so we followed this.