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

Just turning of mail and deleting the accounts and app would not necessarily decrease any caches in system data. The test would be to delete the app(s), backup the device, erase the device and then restore from backup. Mail would not be installed and System Data size would reflect any changes from caches being deleted.

Mail app, however, has its own unique category and generally doesn’t cache any data in System Data.

I recently discovered a simple and effective method through Google AI.

The method is to turn on Airplane Mode to cut off all network connections. Then go to Settings and disable Auto Date & Time. After that, manually set the year forward by 1–2 years so that various stored system files, such as logs, reach their retention expiration.

Then just leave it for about 2–3 minutes.

Unnecessary system files will gradually be deleted.

In my case, the storage used by these files went from 50 GB down to less than 5 GB.

My thread on this topic has been closed but I wanted to report back that after upgrading to 26.6 my ballooning system data stopped ballooning. Apparently. So far so good.

Since iOS 26.0 came out I was having to backup and restore my 17 Pro Max semi weekly. (Never used betas).

I tried removing all apps and deleting apps and followed all the good advice I found here but my intuition was always telling me it was an iOS problem. I have no proof of that accept that my system data problem suddenly after updating to 26.6

I was on my umpteenth backup & restore when 26.6 went live. usually I would try to wait for iOS updates, before starting to backup & restore (because in addition, iOS updates would stall on this device too; also requiring a backup and restore). It just so happens that my phone filled up, and 26.6 was available, and I had the luxury to spend 20 hours waiting for my 2TB phone to fully restore after this was all done.

my system data hasn’t gone over 27-28 GB since the day 26.6 went live on my device. Fingers crossed.

just had to come here and report back. And maybe vent a little. I can’t believe this story is real btw, but it is - I’m proofreading before posting and SMH at my own experience) - Thanks.

System Data taking up 1 TB on my iPhone a… - Apple Community

"I also found my iPhone 13 mini has a 60 gb + system data cache when updating to 26.0 so I tried the date trick, didn’t really work, bit the bullet and erased and purged my iPhone and reset up to get 26 on it, now updating to 26.4.1 and the system data is now ballooned to 61 gb. There seems to be a bit of an issue with iPhone 13’s and the system data cache!"

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Clearing system Data:

This is nothing of a glitch. Formerly called "Other", System Data is created for so that apps can open quicker and operate more efficiently. Unfortunately, there is no way to determine why, nor when these were created. So, to learn how to clear it, use my User Tip: How to Clear "System Data" in your iPhone's Storage: - User Tip

Are you referring to iCloud storage or your iPhones internal SSD storage? Many people confuse the two and they have two entirely different solutions. Please post a screenshot of your internal or iCloud storage so we can accurately determine what you’re experiencing and provide the best possible solution.

I never used my MacBook to update iOS. I did it from the Settings app on my iPhone.

Once the update completed, my system data usage dropped sharply. Restarts didn't help my issue before, nor did the system time change. Restoring was going to be my absolute last resort if the update didn't help things (which it surprisingly did, implying it was an iOS bug all along.)

NetSecNW wrote:

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.

How did you update, OTA or on a computer?

"[...]I think it’s hilarious that apple doesn’t give us a way to clear or at least debug and monitor this part of the filesystem. A complete restore from backup always takes a few hours in my case…"

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Clearing System Data:

Clearing System Data:

That's the way it is. So, turn off all network connections, and perform this in Safe Mode --that way, less network data traffic will occur, and login items will not open at login. For reference, see my user tip: How to Clear "System Data" in your iPhone's Storage - Apple Community

Just for the Record:

This has been Apple's method since the late 2010s. On a phone call with Apple Support in late 2019, Apple ran me through the fix, and then I authored the User Tip, once had earned the points to do so, making a few modifications over the years, as new releases came about. See here: How to Clear "Other" in your iPhone's Storage - Apple Community

I also found my iPhone 13 mini has a 60 gb + system data cache when updating to 26.0 so I tried the date trick, didn’t really work, bit the bullet and erased and purged my iPhone and reset up to get 26 on it, now updating to 26.4.1 and the system data is now ballooned to 61 gb. There seems to be a bit of an issue with iPhone 13’s and the system data cache!

Updated my iPhone 17 Pro this morning to iOS 26.1, system data immediately went from 64GB to 8GB but now after 10 hours we are already back to 12GB...

Let's wait and see but I am not confident at all...

NetSecNW wrote:

I updated OTA. Had to delete a shed load of apps to create the 14Gb space needed for update. Took over and hour to update. Managed to re-install all my apps now. Bad design.

Backup and restore may have taken less time.

Same here. On my iPhone 17 Pro Max system data uses around 65 GB of data. I already restored from backup three times. But system data keeps growing to this level in about a week. I also think that in my case it is related to the App Icon redraw bug. Every time the app icons turn blank and redraw the system data increase by 1-2 GB. I think it’s hilarious that apple doesn’t give us a way to clear or at least debug and monitor this part of the filesystem. A complete restore from backup always takes a few hours in my case…

You stated that you just updated to iOS 26.2.1. It’s normal for System Data (cashes) to grow for the first 48 to 72 hours. This reflects the normal indexing, syncing and iCloud activity that is taking place. System Data should stabilize after that period and you can monitor for abnormal increases in System Data size.

I was about to do your workaround, but I found out the iOS 26.0.1 update fixed my issue! I checked my System Data after the update and found it freed up my space to just under 20 GB (from 108.5 GB!)

maybe set your forum default sort order to "Oldest" in your user preferences to follow the thread as it was posted.

Then look at my post above yours.