How to Free Up Space on iPhone for an iOS Update
To free up space for an iOS update, go to Settings > General > iPhone Storage, tap the largest items first (usually Photos, large apps, and downloaded videos), and offload or delete them until you have a few gigabytes free; an iOS update typically needs roughly 5–8 GB of temporary working space even though the final download is smaller. This guide is for anyone stuck on "not enough storage to install" who wants the fastest, safest way to make room without wiping their phone.
TL;DR
- iOS needs more free space than the update file size because it unpacks the update before installing.
- Check Settings > General > iPhone Storage and clear the biggest offenders first: large apps, downloaded videos, and Photos.
- "Offload App" frees space while keeping your documents and data, so it's a low-risk first move.
- Deleting and reinstalling a huge app (often TikTok, games, streaming apps) frees several GB instantly.
- If you only need space temporarily, free it for the update, then reinstall offloaded apps afterward.
Why does iOS need so much free space to update?
The number you see in the App Store or in Software Update is the download size, but the install needs much more. iOS downloads the update package, verifies it, unpacks it, and then writes the new system files over the old ones. That unpacking step needs scratch space, so a 3 GB download can require 5–8 GB free to complete.
This is also why your iPhone may say "This update requires X GB of available storage" with a number bigger than the download. If you free exactly the download size, the install can still stall.
| Update type | Typical download | Free space to keep ready |
|---|---|---|
| Minor point update (e.g. 18.5.1) | 1–2 GB | 4–5 GB |
| Major version (e.g. iOS 18 to 19) | 4–7 GB | 8–12 GB |
| Big feature update with new apps | 5–8 GB | 10–14 GB |
If you can clear a comfortable buffer above the requirement, the update is far less likely to fail partway through.
How do I see what's taking up space on my iPhone?
Apple gives you a clear breakdown built into Settings.
- Open Settings > General > iPhone Storage.
- Wait a few seconds for the bar at the top to calculate.
- Scroll down to the app list, which is sorted largest to smallest.
- Tap any app to see how much is the app itself versus its "Documents & Data."
The colored bar shows categories like Apps, Photos, Media, and System Data. Photos and Media are usually the biggest, followed by streaming and social apps that cache a lot. Note the three or four largest items, because clearing those gets you to the finish line fastest.
What should I delete first to make room?
Work from biggest to smallest, and start with things you can easily get back.
- Offload a big app you don't need right now. In Settings > General > iPhone Storage, tap an app, then tap Offload App. This removes the app binary but keeps its data, so reinstalling later restores everything.
- Delete and reinstall your largest app. For apps like games, TikTok, or streaming services, the cache can be several GB. Tap Delete App, then reinstall it from the App Store after the update.
- Clear downloaded videos and music. In the TV, Music, Netflix, and Podcasts apps, remove offline downloads. These are often the single largest hidden chunk.
- Empty Recently Deleted in Photos. Open Photos > Albums > Recently Deleted, then delete the items permanently. Deleted photos sit here for up to 30 days and still count against storage.
- Clear Safari website data. Go to Settings > Apps > Safari > Clear History and Website Data (or Settings > Safari on older iOS versions).
If you back up your photos, deleting some local copies is the biggest single win. See how to delete photos from your phone but keep them in the cloud before you bulk-delete anything.
Can I free up space without deleting anything important?
Yes. The goal is temporary headroom, so lean on reversible moves first.
- Turn on Optimize iPhone Storage for Photos. In Settings > Apps > Photos, choose Optimize iPhone Storage. Full-resolution originals move to iCloud and lighter versions stay on the device. (This needs enough iCloud space; read the truth about Optimize iPhone Storage so you know the trade-offs.)
- Offload unused apps automatically. In Settings > App Store, enable Offload Unused Apps.
- Delete large message attachments. In Settings > General > iPhone Storage > Messages, review the largest photos, videos, and GIFs and delete the ones you don't need.
- Update over a computer instead. Connecting your iPhone to a Mac (Finder) or Windows PC (Apple Devices app) lets you update with far less free space on the phone itself, because the computer handles the unpacking. This is the best option when you genuinely can't free enough room.
If your storage looks full even though you don't see why, the culprit is often System Data or cached files. Read what is System Data on iPhone and Android, and can you delete it.
Is it safe to use a cleaner app to make room for an update?
Here's the honest version. iOS already manages a lot on its own: it purges some app caches automatically when storage runs low, and "Offload App" plus "Optimize iPhone Storage" are built-in tools that do real work. No third-party app can reach into protected system files or delete the iOS update's working files for you, and any app promising to "clean System Data" with one tap is overselling.
What a cleaner like Cleanor actually adds is speed and visibility on the messy part: finding duplicate and near-identical photos, large videos, and screenshots you forgot about, then letting you review and delete them in bulk. That's usually where the real gigabytes hide, and scrolling Settings by hand is slow. Cleanor works inside Apple's photo permissions and only deletes what you confirm, so nothing leaves without your review. What it cannot do is bypass the update requirement, recover the phone if you've ignored backups, or magically shrink the OS. For the trade-offs in plain terms, see the truth about cleaner apps and whether they're safe.
FAQ
How much storage do I need to update my iPhone?
Keep more free than the download size shows, because iOS unpacks the update before installing. As a rule of thumb, allow 5–8 GB free for a major version and at least 4–5 GB for a point update. If your iPhone names a specific requirement on the Software Update screen, treat that as the minimum and add a buffer.
Why does my iPhone say not enough storage when the update is small?
The size shown is the download, not the total space needed to install. The system needs extra room to verify and unpack the package, so a 2 GB update can require several gigabytes free. Free a few extra gigabytes beyond the stated number and the install should proceed.
Can I update my iPhone using a computer to avoid freeing space?
Yes. Connecting to a Mac via Finder or to a PC via the Apple Devices app lets the computer do the unpacking, so your phone needs much less free space. This is the most reliable route when you truly can't clear enough room on the device.
Will deleting apps for the update lose my data?
Not if you offload instead of delete. Offload App removes the app but keeps its documents and settings, which return when you reinstall. Delete App removes the data too, so for things like chat apps, back up first.
Where to start
The fastest path is usually photos and one or two oversized apps. Open Settings > General > iPhone Storage, offload your biggest app, clear offline downloads, and empty Recently Deleted in Photos. That alone often clears the buffer an update needs.
For a repeatable routine so you're never stuck before an update again, follow our guide to clean up phone storage, and if duplicate and bloated photo libraries are your real problem, Cleanor for iOS finds and clears them in bulk after your review. To decide what goes first, start with storage full: what should I delete first.