Quick answer
The full iOS 27.2 beta 4 package is 10.88 GB to 13.72 GB depending on your iPhone, with the iPhone 18 Pro models at the top. Updating over the air needs that space on the iPhone plus room to unpack it. Installing an IPSW from a Mac or PC keeps the big file on the computer, so it suits iPhones that are nearly full.
How big is the iOS 27 beta for each iPhone
The current beta is iOS 27.2 beta 4, build 24B5110a, released on 13 October 2026. These are the sizes of Apple's full restore files (IPSW) for that build, taken from the files on Apple's servers. They show how much data a full install involves. The over-the-air package that Settings downloads is a separate file, and Software Update shows its exact size before you start.
| iPhone | iOS 27.2 beta 4 IPSW |
|---|---|
| iPhone 18 Pro, iPhone 18 Pro Max | 13.72 GB |
| iPhone 17 | 13.07 GB |
| iPhone 17 Pro, iPhone 17 Pro Max | 13.04 GB, 13.02 GB |
| iPhone 16 Pro, iPhone 16 Pro Max | 12.86 GB |
| iPhone Air | 12.82 GB |
| iPhone 16, iPhone 16 Plus | 12.75 GB, 12.72 GB |
| iPhone 17e | 12.66 GB |
| iPhone 15 Pro, iPhone 15 Pro Max | 12.44 GB |
| iPhone 16e | 12.10 GB |
| iPhone 14 Pro, iPhone 14 Pro Max | 11.53 GB, 11.50 GB |
| iPhone 15, iPhone 15 Plus | 11.52 GB |
| iPhone 13 Pro, iPhone 13 Pro Max | 11.48 GB |
| iPhone 12, iPhone 12 Pro, iPhone 12 Pro Max | 11.44 GB, 11.44 GB, 11.40 GB |
| iPhone 13 mini, iPhone 13, iPhone 14, iPhone 14 Plus | 11.35 GB to 11.37 GB |
| iPhone 12 mini | 11.33 GB |
| iPhone 11 Pro, iPhone 11 Pro Max, iPhone SE (3rd generation) | 11.10 GB |
| iPhone 11 | 10.91 GB |
| iPhone SE (2nd generation) | 10.88 GB |
Each model's page in our IPSW library lists every build with its exact size and checksum, for example the iPhone 16 Pro IPSW page or the iPhone 11 IPSW page.
Is the beta bigger than the public release
A little. Comparing the restore files for the same iPhone, the 27.2 beta is a fraction of a gigabyte larger than the public iOS 27.0.1 (24A446), and iOS 27 as a whole is larger than iOS 26.6.1 RC (23G82).
| iPhone | iOS 26.6.1 RC | iOS 27.0.1 | iOS 27.2 beta 4 |
|---|---|---|---|
| iPhone 11 | 9.82 GB | 10.71 GB | 10.91 GB |
| iPhone 13 | 10.32 GB | 11.14 GB | 11.35 GB |
| iPhone 15 Pro | 11.25 GB | 12.23 GB | 12.44 GB |
| iPhone 16 Pro | 11.36 GB | 12.31 GB | 12.86 GB |
| iPhone 17 Pro | 11.52 GB | 12.73 GB | 13.04 GB |
The practical takeaway: moving from iOS 26 to iOS 27 costs you roughly a gigabyte more for the system on most models, and the beta adds a little on top of that.
How much free space to leave
Plan around the install method, because the two routes put the big file in different places.
| Over the air (Settings) | IPSW from a computer | |
|---|---|---|
| Where the update is stored | On the iPhone | On the Mac or PC |
| Space needed on the iPhone | The download plus room to unpack and install it | Much less, since the file stays on the computer |
| Space needed on the computer | None | The IPSW size above; leave about twice that free |
| First install from iOS 26 | A large, full-size package | The full IPSW |
| Beta-to-beta updates | Usually a much smaller update | The full IPSW every time |
| Best for | Most people with room to spare | Nearly full iPhones, or repeated failed downloads |
You do not need to work the numbers out yourself. Software Update shows the size of the update for your iPhone, and if there is not enough room it tells you so and the install does not start. Use that message as your target, then keep a few gigabytes extra so the iPhone is not running on empty afterwards.
How to check your free space
- Open
Settings › General › iPhone Storage. - Wait for the bar at the top to finish loading. The numbers keep shifting for a few seconds while iOS adds everything up.
- Read the used and total figures at the top; the difference is your free space.
- Scroll to the bottom to see how much System Data is using.
If System Data looks unusually large, restart the iPhone and check again. A restart clears some temporary files, and the figure often drops.
How to free up space quickly
Start with the steps that free the most room and stop as soon as you have enough. Our full guide to cleaning up iPhone storage covers the rest.
Offload apps you rarely use
In Settings › General › iPhone Storage, tap a large app you have not opened in a while and choose Offload App. The app is removed but its documents and data stay, so reinstalling picks up where you left off. Games are usually the biggest items in the list. To have iOS do this automatically, turn on Offload Unused Apps under Settings › Apps › App Store.
Let iCloud hold your full-size photos
If you use iCloud Photos, turn on Optimize iPhone Storage under Settings › Apps › Photos. Full-resolution originals stay in iCloud and the iPhone keeps smaller versions until you open them. On a large library this frees a lot of space without deleting anything.
Clear out Messages attachments
Open Settings › General › iPhone Storage › Messages and review the large attachments, photos and videos. Busy group chats often hold years of media.
Remove downloaded video, music and podcasts
Films and series downloaded for offline viewing take up a lot of room. Check the downloads section of each streaming app, plus Music and Podcasts.
Delete an old, uninstalled iOS update
If an earlier update downloaded but never installed, it sits in the iPhone Storage list. Tap it and choose Delete Update. You can download the newer one afterwards.
Clear Safari's website data
Under Settings › Apps › Safari, tap Clear History and Website Data. You will be signed out of websites, and the gain is usually modest, so leave this until last.
What happens to storage after the beta installs
Expect the numbers to look odd for a while. After a major update, iOS rebuilds its search index, the Photos library index and other system databases in the background, and System Data can look inflated until that finishes. Leave the iPhone on Wi-Fi and power, ideally overnight, before judging how much space the beta really takes.
Beta builds also collect more diagnostic information than public releases, which Apple uses to fix bugs. That is part of why the beta files are slightly larger. When you move to a public release, the system is replaced with the leaner public build.
If you still cannot make enough room
- Install from a computer. Download the IPSW for your exact model from our iOS 27 beta IPSW download page, connect the iPhone, hold Option (Mac) or Shift (Windows) and click Check for Update in Finder or the Apple Devices app, then choose the file.
- Back up, erase and restore. Back up the iPhone, erase it with
Settings › General › Transfer or Reset iPhone › Erase All Content and Settings, install the beta on the empty iPhone and restore your backup. This also clears out accumulated System Data. Read our guide to backing up before the iOS 27 beta first, because a backup made on the beta cannot be restored onto iOS 26. - Wait for the public release. If space is tight and you do not need the newest features, iOS 27.0.1 is already available as a regular update.
What to do next
Once you have the room, make your backup, then follow our step-by-step guide to installing the iOS 27 beta.
Frequently asked questions
How big is the iOS 27 beta download?
The full restore file for iOS 27.2 beta 4 (24B5110a) ranges from 10.88 GB for the iPhone SE (2nd generation) to 13.72 GB for the iPhone 18 Pro and iPhone 18 Pro Max. Newer and Pro models get the larger files. An over-the-air update from one beta to the next is usually much smaller, because it only carries the changes. Software Update shows the exact size for your iPhone before you tap Download.
How much free space do I need to install the iOS 27 beta?
It depends on how you install. Over the air, the update downloads to the iPhone and needs working room on top of the download, so a jump from iOS 26 needs much more free space than a small beta-to-beta update. Software Update tells you if there is not enough room and the install will not start. Installing with an IPSW from a computer keeps the large file off the iPhone.
Can I install the iOS 27 beta on a 64 GB iPhone?
Yes, as long as the model supports iOS 27 and you can free enough space. On a small iPhone the simplest route is often an IPSW install from a Mac or PC, because the 11 GB or so restore file sits on the computer rather than the phone. Offloading large apps and turning on Optimize iPhone Storage for Photos are the quickest ways to make room first.
Why is System Data so large after installing the beta?
After a major update iOS rebuilds its search, Photos and system indexes, and caches can grow while that happens, so System Data often looks inflated for a while. Give the iPhone time on Wi-Fi and power, then restart it, which clears some temporary files. If System Data stays very large for days, a backup, erase and restore is the reliable way to reset it.
Does turning off Beta Updates free up storage?
No. Turning off Beta Updates only stops new beta builds from arriving. The beta you have installed stays on the iPhone until the next public release with a higher version number replaces it. To remove the beta completely you need to restore iOS 26.6.1 RC with a computer, which erases the iPhone, and then restore a backup made before you installed the beta.
What happens if I try to install without enough space?
Software Update tells you more storage is needed and the installation does not start, so nothing is lost. Free up space and try again, or install from a computer with an IPSW instead. Do not try to force the update through with third-party tools. A failed install can leave the iPhone needing a recovery-mode restore, which is far more work than clearing a few apps.