Can a USB key provide temporary storage for iPhone 12 iOS update?

No, plugging in the USB drive will not give you more room on the phone to do the update. You need to have enough free space on the phone itself.

No. The update will be downloaded to and unpacked on the iPhone's internal storage. No way for it to use the USB drive.

You can however, move files and data out the USB drive to release some storage space on the iPhone and make room for the update.

No

You need to make space, such as uninstall apps like Whatsapp (back up first internally) You Tube, Anything that creates a huge cache. Also ensure your Photos are optimised using ICloud.

If necessary, back up, erase the phone completely to factory settings, set up without reference to the backup and it should update.

Erase again then restore the backup on setup the same day.

You may be able to update by attaching your phone to a computer, and it does not have to be a Mac. That usually requires less free space on the phone than an "over the air" update.

See the first two links in this Apple article: https://support.apple.com/en-us/118575

First restart the iPhone. This will engage the cleanup process and likely release some of the used of space from System Data, iOS is unlikely to be reduced significantly however.

Then check your apps, and see if you can temporarily offload the larger ones.

1. Open the Settings app on your iPhone.
2. Tap General.
3. Select iPhone Storage to load a list of your installed apps and see how much space each one uses.
4. Scroll down the list and tap the specific app you want to offload.
5. Tap Offload App, then tap Offload App again to confirm

https://youtu.be/bwjcYyCneNc

Ohh2759 wrote:

The problem is that most of my storage is being taken up by IOS and system data

https://discussions.apple.com/content/attachment/e1303121-4446-4e3f-b2eb-0b788247fcf6

i did the math and I only have about 19 GB left if I don’t have any apps installed

See my answer about backup, erase, setup etc. you really need to get rid of those grey bars, excess iOS and System caches.

Yes you do have apps installed (red), you may not be able to delete those if Apple's stock apps.

Problem is that offloading an app like WhatsApp will free off maybe 400MB app, but leaves 10, 30, maybe 100GB (teenagers) of data on the phone.

Offloading needs to be taken out of the toolbox IMHO, it is ineffective.

Any suggestion we can offer is going to be a bandaid solution. Sure you can restore your iPhone and reduce System Data, but it will grow over time. And you can certainly update your iPhone using your computer. But nothing you do will compensate for owning an iPhone with only 64GB of storage to begin with.

One of the MOST overlooked items when people buy an iPhone is storage. Once purchased, the storage on iPhone is fixed at purchase. And in today's world, 64GB is simply not enough. Today, Apple sells the newest model iPhones starting with 256GB of storage, which is 4 times more storage than your iPhone came with. And even that, in my opinion isn't enough, which is why for the last couple years, my new iPhones have been purchased with 512GB.

You really need to give serious consideration to upgrading to a new iPhone, and this time buy the most storage you can afford. Our storage needs will only grow as more features are added. No one has EVER come to this forum and complained they have too much storage. But daily, we see people come here looking for solutions because they don't have enough, like in your situation.

The problem is that most of my storage is being taken up by IOS and system data

i did the math and I only have about 19 GB left if I don’t have any apps installed

[Edited by Moderator]

You have 6.2 gig left, not 19. You definitely need to clear some stuff off your phone.

I agree. However there looks to be around 20GB of iOS nd 20GB of system data. Offloading will not get that down from a total of about 40 to nearer 15GB, only erase to factory and reinstall backup.

LD150 wrote:

Problem is that offloading an app like WhatsApp will free off maybe 400MB app, but leaves 10, 30, maybe 100GB (teenagers) of data on the phone.

Offloading needs to be taken out of the toolbox IMHO, it is ineffective.

True, but since there doesn't appear to be anything else to delete, that's the easiest thing and some of the larger apps apps my release a GB or so, and after deleting a few o those you get some data back even if there documents and data remains on the device.