How do I reset my iPhone? Can I force-reboot my frozen iPhone? How can I restore an old back-up on my iPhone or iPad? Is it possible to retrieve data from a wiped iPhone or iPad?
In this tutorial we will show you how to reset an iPhone or iPad - perfect if you need to wipe an iPhone or wipe an iPad because you are selling it. Alternatively, if your iPhone or iPad has frozen we can show you how to reset it and restore it from a back up. Here's how to reset, restore and reboot your iPhone or iPad next time it hangs. Read on to find out how to erase your iPhone or iPad, and restore everything again afterwards. 

How to fix a frozen iPhone or iPad

If you've ever watched the IT Crowd, you'll be well versed in the mantra "Have you tried turning it off and on again?", which is the stock response used by Denholm Industries' IT department to solve all computer-related ills.
In real life… well, strangely enough it's often the way to fix problems that occur on your iPhone, iPad or even Mac. Modern electronic devices are very complicated, and can get themselves into a bit of a confused state from time to time. Resetting can clear out random problems that cause the device to get stuck in a loop, appear sluggish or otherwise impair their performance. It's not a guarantee, but you'd be surprised how often it works.
For bigger issues though, you might find that a trip to the Apple Store is in order, and this often results in a fixed device but with all the data wiped clean. To solve this it's vitally important that you backup your iPhone either with iCloud or iTunes. With that safety net in place you can restore your iPhone when it starts to have problems. Read on to find out how to restart your iPhone if it's completely unresponsive, backup your iPhone before resetting it and more.
Read next: How to reset a Mac
And: iPhone problems and fixes: frozen iPhone screen, stuck in recovery mode, water damage

Restarting an unresponsive iPhone or iPad: What to do if your iPhone has crashed

If your iPhone or iPad has become unresponsive, or you've shut it down and it won't turn on again, all is not lost. There is a feature on iOS devices that can be used when the normal modes of operation aren't working. Thankfully they are very easy to do, and require no tools or specialist knowledge. In fact you just need two fingers and about twenty seconds.
To restart your iPhone or iPad hold down the Home button (the one on the front of the iPhone or iPad) and at the same time hold down the power button (aka the lock switch) until you see the Apple logo appear on the screen. Now you can let go of the buttons and let your device complete its start sequence. This is called a hard reset, and should hopefully fix any issues you were having. If things are still not as they should be, then it might be a good idea to restore an old backup, as some of your files could be corrupted and causing the issue. Read on to find out more.
Read next: How to put an iPhone into DFU mode

How to back up your iPhone or iPad before you wipe it

If you want to start with a clean slate, then there are a few steps to take. First of all make sure you have a backup ready, and we're about to show you how to do so.
You can use either iCloud or iTunes to backup your iOS device. For iCloud go to Settings > iCloud > Backup and ensure that the feature is enabled. To see when the last backup was run look under the Back Up Now option where the date and time should be displayed. If you haven't done a backup before you can tap the Back Up Now button and follow the instructions.
To use iTunes you'll need to plug your iPhone or iPad into your PC or Mac using the charging cable. Click on the iPhone or iPad icon in the top left corner of iTunes, under the Play button.
Read next: Complete guide: How to update iOS on iPhone or iPad

How to factory reset your iPhone or iPad: How to reset your iPhone or iPad

Once you're confident that you've backed up your iPad or iPhone, you're ready to perform a factory reset. This will completely wipe your device which is why having a backup is so important.
A factory reset can help resolve issues with your iPhone or iPad if it's crashing or freezing, but it is also what you'll want to do if you need to wipe your iPhone or iPad before selling it, or passing it on to a family member or friend.
When selling an iPhone or iPad, it's absolutely vital that you delete all the sensitive data stored on it. If not, an unscrupulous buyer could gain access to your social media profiles, your financial information and even your personal photos and videos, enabling them to browse through your private moments or steal your identity.
Luckily it's very easy to completely wipe an iPad or iPhone. Simply follow the steps in this tutorial and your data security will be assured.
To reset your iPhone or iPad go to Settings > General > Reset and then select Erase All Content and Settings.
After typing in your passcode if you've set one, you'll get a warning box appear, with the option to Erase iPhone (or iPad) in red. Tap this.
You'll need to enter your Apple ID password to confirm the action, then the iPad or iPhone will wipe everything off its storage and go back to the initial setup screen you saw when you first used the device.
You can also fully reset your iPhone or iPad through iTunes. When you plug in your iOS device, you should be able to see a 'Restore iPhone' button, which will fully reset the device.
Your iPhone or iPad is now ready to sell. For more, read How to back up an iPhone
We've rounded up links to all our iPhone tips and tutorials here: iPhone tips and tutorials, everything you need to know

How to wipe data from an iPhone or iPad: Deleting apps and other items individually

That's the quick method, but if you just want to free up some space a full wipe clearly isn't the best option.
To look at the biggest culprits filling up your storage allocation, go to Settings > General > Usage. iOS will tell you firstly how much space you're using and how much is available, and will then list the apps taking up the most space.
Remember that these listings include associated documents and files as well as the app itself, so Photos and Music are likely to be up near the top. Instead of deleting the app (which you wouldn't be able to do anyway, with Apple's preinstalled apps) you could go into the app in question and clear out some old photos or songs, for example.
To delete an app you're finished with, click it in this list, then Delete App and confirm. Alternatively, from the Home screen you can tap and hold any icon, then tap the X at the top left of an app to delete the app. (If it hasn't got an X, you can't delete it.)

How to restore an iPhone or iPad: iCloud backup

If having erased the content of the phone you intend to keep using it, you can restore the content to your phone from your backup.
With the factory reset completed you'll need to go through the setup of your iPhone again from the beginning; entering your details, WiFi password and a few other things until you reach the page where you're asked how you want to 'Set Up iPhone'. You have the three options – Set Up as a New iPhone, Restore from iCloud Backup or Restore from iTunes backup – so select the iCloud option and you'll be prompted to enter your iCloud account details. Once you've done this, and agreed to the terms and conditions, your iPhone will begin restoring all of your data.
Obviously this could take a while if you have large backups or a slow internet connection, so don't attempt this if you're in a hurry. When the backup is completed your iPhone will reboot, and then it will start the larger job of downloading all of your apps.

How to restore an iPhone or iPad: iTunes backup

As with the iCloud instructions we've already outlined, follow the steps up to the 'Set Up iPhone' screen, then select Restore from iTunes. You'll be prompted to Connect to iTunes, so plug in your iPhone and you'll see a screen on iTunes that gives you the option to restore a backup. Click continue and your iPhone will be set up automatically, with the apps being restored from the iTunes backup. When it's finished, you'll have a freshly cleaned system and hopefully any problems that you were encountering before will be a thing of the past.

What to do if your iPhone or iPad isn't backed up

If you're worried that your iPhone or iPad wasn't backed up, chances are that there is a backup that you were unaware of. To find out if you are backing up to iCloud (you get free 5GB of space) go to Settings > iCloud and tap on Storage. Wait a few seconds for Manage Storage to show up and tap on that. Here you will see your various backups for your iOS devices (there might even be one for an old iPhone that you could delete if you need more space).
One of the backups should say that it is This iPhone or This iPad. Tap on that and you can see what is, and isn't being backed up. You can basically turn things on and off so that they don't take up your full 5GB, or you can pay a few pounds a month for more storage.
You may think that some of those apps don't need to be backed up, after all, you will be able to download them again from the App Store as you already own them. But note that the data may include saved data for games, and other settings and preferences that you would prefer not to lose.
To check when your iPhone last backed up, go to Settings > iCloud > Backup and look at the date and time of the last back up. It will have happened the last time you plugged your iPhone in to charge and had WiFi access available. It happens automatically.
If you find that you aren't backing up this way, we recommend that you go to Settings > iCloud > Back up and turn iCloud Backup On as this is the simplest way to back up and means that you always recover the data on your phone no matter where you are, all you will need is a connection to the web.

Data recovery: Is it possible to rescue data from a wiped iPhone or iPad?

Almost certainly no, which is why you need to be sure before resetting it. The data on an iOS device is automatically encrypted, and wiping the device destroys the encryption key, making it more or less impossible to get anything back when it's been fully erased and reset without access to a backup.
In an emergency you could try speaking to someone at tan Apple Genius Bar, but it's a long shot to say the least. (This applies to a full erase/reset, mind you – in other circumstances, such as data corruption, a malfunctioning device and so on, the experts may be able to help.) This also reinforces out frequent advice to back up regularly.