System Data is taking up 54.91 GB on my iPhone 13 Pro with iOS 26

TLDR: Use a computer to do the update if you are low on space; ios 26.1 does not seem to have the same space-hogging bug that 26.0.x did.

I had a similar issue- system data took up massive amounts of space on my iphone 14 pro with 128gb of storage forcing ios to offload apps and "optional" data (like offline language, maps, etc.) frequently, and leaving me unable to store offline music or videos and forcing most of my apps to be in an offloaded state. I've been using iphones since the beginning and I have never ever run out of space for apps and music. I was unable to install the ios 26.0.1 update without deleting a ton of stuff off my phone, so I was desperate to try the ios 26.1 update hoping it would fix the problem... .of course with 118gb used out of 128 it refused to install. Luckily I had my mac handy and I was able to do the ios update using the mac and it worked without any problems. And so today, without deleting or offloading anything vs. yesterday I now have 40gb free. This leads me to agree that there was a bug in iOS 26.0 and .0.1 that is now resolved in 26.1. For anyone blocked from upgrading to 26.1 due to storage being too full of ios data, I recommend using a computer to do a backup and update.

The abnormal growth and speed of growth can be traced to both third party apps and Apple apps. Third party apps frequently use System Data for their caches.

Common apps that do this are streaming apps like YouTube, Spotify, Amazon Video, and Netflix etc. Social media apps like Facebook, Instagram, WhatsApp, TikTok, Discord. Sometimes when you just delete the app, it moves its cached data to System Data.

Apple maybe partially to blame too. Safari and Messages (iMessage) cache data too. When the iOS is upgraded or updated background syncing, indexing etc. can cache large amounts of data.

Whatever apps are doing this, they can’t do it without consuming battery capacity. What apps are using the most battery capacity on a day to day basis?

So since 26.2 I needed to recover my iPad three times now. Finally it‘s fixed now. I hav several old apps which where not installed after recovering to a backup because they are not available in the appstore any longer. They where shown with their app icon and the download arrow and some where slightly ghosted and showing ‚waiting‘ forever as they would be downloaded actually. Deleting these apps instantly stopped the growing system data even these apps where not really installed. I really did not know anymore how cold my iPad could be… the system seemed to try anything for downloading these apps and somehow write the system gull of log files.

So if you are stuck in a similar problem and turning of AI did not help, try going through all of your apps and delete failing stuff.

Maybe I have a clue. I had to restore my phone because the system data had grown to nearly 200GB and things were getting slow and jerky. (First I tried to upgrade to 26 beta hoping that would clear it out, but the upgrade failed!) I decided to add back some of the larger things I keep on the phone gradually after watching the system data to see if it was stable for a day. When I copied a whole bunch of movies into my movie player app (Infuse) suddenly the system data went from its stable 20GB up to 120GB and then nearly 200GB. When I deleted some but not all of them it just as suddenly went back down. My guess is that it was indexing the movies for search and something about one of the files made it blow up. Next I could try turning off search in content for Infuse and see if that helps.

Restoring is the usual method of reducing delinquent system data. It can be caused by gaming apps, social media apps, or beta testing. It would not be reduced by an update normally unless using a mac ti update it.

Same issue. System Data grew from 50 GB to 69 GB over two weeks. Every day I would delete 1-2GB of videos, and every night the space would fill up. I was unable to try the clock trick, moving the time ahead, due to time being locked due to "device restrictions".

Updating to iOS 26.1, finally fixed the issue, dropping System Data under 15GB.

I’ve never enjoyed that kind of reduction by OTA update, glad it worked for you.

Fir the rest of us, if the space is needed then backup, erase, restore,

If the System Data growth is from wallpaper and lock screen manipulation, only a full reset works so far.

System time and ProRes tricks only ever clear 1-2GB for me.

I’m averaging one full reset a week 🤷🏻‍♂️

Yes, but the only way to shrink System Data back to normal size is to erase the device, in most cases.

Rcinkle wrote:

If the System Data growth is from wallpaper and lock screen manipulation, only a full reset works so far.

System time and ProRes tricks only ever clear 1-2GB for me.

I’m averaging one full reset a week 🤷🏻‍♂️

Gaming, badly behaved social media and beta testing are surely a bigger creator of rogue system data than wallpaper?

Eventually upgraded to 26.1 which took ages. After the phone being on for around 10 minutes the system data usage dropped massively to around 16.5GB. Much better than the 70GB that it was before. Nothing in the 26.1 release notes to say it was a bug.

First turn off AI

If that fails to reduce storage in a few days, use iCloud or other cloud fully on all your data. Sync fully.

You can then restore to factory and set up without a backup

Build from scratch and only install really essential apps as you need them.

Avoid games, AI, and security apps.

-thoraxx- wrote:

It seems to me that IOS 26.2 does not fix this...

Nothing to fix, turn off AI will make a big difference.

And/or

Back Up: How to back up your iPhone, iPad, and iPod touch - Apple Support

Erase & Restore: Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

 if it comes back later after using Games, that is the cause.