Short answer: an iOS update needs several gigabytes free, more than the download size, because iOS unpacks it before installing. The fastest fixes: empty Recently Deleted, delete or compress a few big videos, and offload apps you rarely use. If iOS offers to temporarily remove apps, tap Continue: they come back after the update with their data. If you still can't get the space, update from a Mac or PC, which needs much less room on the iPhone.
Steps
- Open Settings › General › Software Update and note the update size. Aim for that much free space plus a few gigabytes.
- Open Settings › General › iPhone Storage. If an old iOS update is listed in the apps, tap it and choose Delete Update, then download it again.
- Empty Photos › Collections › Utilities › Recently Deleted (on iOS 18, scroll down to Utilities). This is often several gigabytes on its own.
- Delete or compress your biggest videos. A few long 4K clips can free 5–10 GB.
- Offload two or three big apps you rarely use: iPhone Storage › [app] › Offload App. Their data stays.
- Try the update again. If iOS asks to temporarily remove apps, tap Continue.
- Still not enough? Connect the iPhone to a Mac (Finder) or a Windows PC (Apple Devices app or iTunes), select the iPhone and click Check for Update. The computer downloads and prepares the update.
Where to find space fast
| Source | Typical space freed | How |
|---|---|---|
| Recently Deleted | 1–10 GB | Select › Delete All |
| A few long videos | 2–10 GB | Delete, or compress the ones you keep |
| Unused apps and games | 1–10 GB | Offload App (data kept) |
| Messages attachments | 1–5 GB | iPhone Storage › Messages › Review Large Attachments |
| Streaming downloads | 1–20 GB | Remove offline episodes and playlists in each app |
| Old downloaded update | 3–7 GB | iPhone Storage › iOS update › Delete Update |
Does updating delete anything?
No. A normal iOS update keeps your photos, messages, apps and settings. It's still smart to back up first (Settings › [your name] › iCloud › iCloud Backup › Back Up Now), because an update interrupted by a dead battery is the one time things can go wrong. Keep the iPhone charging during the install.
Why the update needs more space than its size
The number on the Software Update screen is the download. iOS also needs room to unpack the update, keep the old system until the new one is verified, and rebuild caches afterwards. That's why an update shown as 6 GB can ask for much more free space. Updating from a computer avoids most of that on the iPhone itself. The same applies to iPads (iPad storage full).
Getting the space with Spaceclear
If Photos is your biggest category, Spaceclear gets you there quickly. Scan, then Clean safely removes exact copies and lookalikes in one review, keeping the best shot of each set. Compress Videos shrinks the clips you keep (date, location and HDR kept). Remember to empty Recently Deleted afterwards. Spaceclear can't clear System Data or old update files; those are the iOS steps above. More ideas: free up storage without deleting anything.
FAQ
How much storage do I need to update iOS?
It depends on the update and your model. Minor updates can need under 1 GB, while a major yearly release often needs 5–10 GB or more free. The Software Update screen tells you how much is missing when there isn't enough.
What does "temporarily remove apps" mean?
iOS removes some installed apps (the app itself, not your data) to make room, installs the update, then reinstalls them. Your documents, logins and settings stay. It's safe to accept, though it can take a while on a slow connection.
Can I update my iPhone without deleting photos?
Yes. Update from a Mac or PC, which needs far less free space on the iPhone, or temporarily free space by offloading apps. You can also move photos to a computer first: see how to transfer photos to a computer.
Updated 2026-11-13