iOS 12 update without iTunes

The error means your iOS version is too old to update directly to iOS 12 wirelessly. You will absolutely need to use iTunes to update there's is no way around this. This does not in any way involve syncing the iPhone to iTunes.

If your iTunes application is very very slow, then there's a different issue going on. Newer iTunes versions have improved responsiveness and performance, and updating the iPhone on a decent internet connection should not take more than 15 minutes if that.

Follow the steps here: Update your iPhone, iPad, or iPod touch - Apple Support

You will need to make sure, the iTunes version on your computer is up to date. You will need iTunes 12.8 on Mac or 12.9 on Windows to update to iOS 12.

Air 2 comes with factory installed iOS 8 so that should support over the air update. Is the device jailbroken? Does it have enough free storage space? If all else fail, your only option is to use iTunes. You don't have to sync any music, photos etc.

It's not about the general wireless update support. It's about something iOS 12 requires for the wireless update that is not available in older iOS versions. I believe iOS 9 and earlier cannot update directly to 12 wirelessly.

@Zagara, its entirely your choice, but seems silly to throw away a perfectly functional device simply because of an application that I admit has had many issues in past, but has been greatly improved recently.

You can go to an Apple Store and ask to use there computers to update if you don't feel like installing iTunes on your computer for any reason.

ShagCA wrote:

I have never heard of that before. Does Apple have an article on this issue (old iOS can't update directly to 12 OTA). I'm thinking the cause may be insufficient storage free space.

No. But I have seen enough posts about it, with images stating as much to prove its not some random issue with it.

There's also this from the support document:

Update your iPhone, iPad, or iPod touch - Apple Support

If you see an error or need more space when updating wirelessly

If you see an error message while trying to update your device wirelessly, learn what to do. If you need more space for a wireless update, you can update using iTunes or delete content manually from your device. Whether you use iTunes or update wirelessly, you'll have the same amount of free space on your device after you update.

Some iOS software updates aren't available wirelessly. VPN or proxy connections might prevent your device from contacting the iOS update servers.

What does iPad say (the exact message) when you check for update?

I have never heard of that before. Does Apple have an article on this issue (old iOS can't update directly to 12 OTA). I'm thinking the cause may be insufficient storage free space.

Zagara wrote:

Trashcan it is then.

Must be nice to just throw away an expensive and perfectly working device just because you are too stubborn to use an app that maybe necessary to get you the upgrade/update you seem to want to need/use.

Absolutely nothing wrong with upgrading/updating iDevices using iTunes on a computer.

I have been upgrading/updating all of my iDevices using this much more reliable method for many, many years.

Do what you will.

What is your iPad model number?

If you live in the same city I live, I'd be more than happy to take that troublemaker device from your hands for $0. Seriously.. do whatever you want with it. It's your device.