However, it’s something of a nuclear option — when you're done, you'll have what amounts to a new iPhone (from a software perspective). Before you get started, it's a good idea to back up your iPhone before you begin. This will allow you to restore your backup once the factory reset is done.
Note: If you're selling or giving away your iPhone, be sure to Turn off Find my iPhone before you reset.
How to factory reset an iPhone
Once your backups are in place, the easiest way to reset your iPhone is in the Settings app.
Step 1: Tap General.
Step 2: Tap Transfer or Reset Phone.
Step 3: Tap Erase All Content and Settings.
Step 4: Tap Continue.
Step 5: Enter your passcode.
Step 6: At this point, your phone will try to back up to the cloud. If it works, you'll be allowed to continue. If not, you'll be prompted to Erase anyway
Ensure the phone was restored
Once the restoration process is complete — a process that may take up to several minutes — check to ensure your phone has been restored to its original factory settings. If done correctly, you’ll once again be presented with the iOS Setup Assistant upon startup, from which you can then restore your phone from a backup or continue the process as if you were setting it up anew. It’s like it just came off the assembly line all over again.
What do the other reset options mean?
When you’re resetting your iPhone, iOS presents you with a host of different options, and it can be confusing deciding which ones to choose. Usually, you’ll want to perform the aforementioned factory reset, but here’s an explanation of what the other options do so that you can choose the best reset for your needs.
Note: If you are selling your phone or turning it over to someone else, the only command that safely erases everything and takes your phone back to its original state is Erase All Contents and Settings.
Reset Network Settings
If you choose this option, you won’t lose all your data, but you will lose your settings and Wi-Fi passwords. Manual settings will disappear, sure, but you’ll still have your pictures, apps, and other content.
Erase All Content and Settings
This is the option we described at the start of this post, which erases everything from your device. Your settings, pictures, apps, and other data will vanish for good — unless you’ve backed up your content.
Reset Network Settings
Sometimes you just need to refresh your network settings to set up a better connection. Choosing this option resets your network settings, flushes the cache, and deletes any temporary files you have stored on your device. It’s great for those who are experiencing trouble with various Wi-Fi connections.
Reset Keyboard Dictionary
While it can often lead to a good laugh, your iPhone’s autocorrect system sometimes hopelessly botches a sentence or word that was fine in its original form. There is still hope if you’re constantly getting typo suggestions and irrelevant words when typing messages. This is a simple resolution to autocorrect failures that involves wiping your keyboard dictionary’s history.
Reset Home Screen Layout
Many users enjoy installing and rearranging apps on their smartphone’s home screen. If you get bored of the same old format, you have a surefire way to make a sporadic yet drastic change. Resetting is a great option if you want to return to your iPhone home screen’s factory default layout.
Reset Location & Privacy
Oftentimes when you’re pushing a bunch of buttons and experimenting with your settings, you can accidentally cause problems. If you need to reinstate your phone’s initial privacy and location settings, you may want to consider this reset. You don’t have to worry about losing any other information in the process.
