You go to film something that matters and the phone refuses. The storage bar is a strip of colors with no instructions, and the obvious fix, deleting photos, is the one that can cost you memories.
Open Settings › General › iPhone Storage, read which category is largest, and start with things you can download again. Then move to large videos, message attachments and unused apps, in that order. Back up photos and videos before you delete them, because a deleted synced photo also leaves iCloud.
Free tool: the video storage calculator shows how much space your videos take at each camera setting and what switching settings would save.
First, confirm which storage is full
Two different warnings use the word “storage.” iPhone Storage Full means the phone’s own space has run out. iCloud Storage Full means your online Apple account is full. Deleting apps fixes the first and does nothing for the second. Buying iCloud+ fixes the second and leaves the phone just as full.
If your warning mentions iCloud, use the iCloud storage guide instead. Everything below is about the phone.
Read the iPhone Storage screen
- Open Settings.
- Tap General, then iPhone Storage.
- Wait for the bar at the top to finish calculating. It can take a minute on a full phone.
- Look at the colored bar and the app list below it. Apps are sorted by size, largest first.
- Tap any app to see two numbers: the App Size (the app itself) and Documents & Data (what it stores).
The bar groups your space into categories. Here is what each one holds, based on Apple’s own definitions:
| Category | What it holds | Can you shrink it? |
|---|---|---|
| Apps | Installed apps, files in “On My iPhone” in the Files app, Safari downloads | Yes, by offloading or deleting apps and clearing downloads |
| Photos | Photos and videos in the Photos app | Yes, after you have a verified copy elsewhere |
| Media | Music, videos, podcasts, ringtones and voice memos | Yes, most of it can be downloaded again |
| Messages | Texts and their attachments | Yes, through attachment review or a shorter keep period |
| Mail, Books, iCloud Drive | Downloaded mail, books, PDFs and iCloud files stored on the phone | Partly |
| System Data / Other | Caches, logs, Siri voices, fonts, the search index, Keychain | Only indirectly; the phone manages it |
| iOS | The operating system | No |
Two cautions before you act. Cached and temporary data may not appear in an app’s number, so the bar and the app list never add up exactly. And when the phone runs low, iOS already removes some temporary files and items you can download again, so free space can jump around on its own.
Work through the list in this order
The order runs from items you can get back with one tap to items you can lose for good. Stop when you have enough room.
1. Use Apple’s recommendations
Near the top of iPhone Storage, tap Show All to see Apple’s suggestions. Each one either has an Enable button or opens a list you review. Read the description before you tap. Offload Unused Apps runs automatically from then on, removing apps you rarely open while keeping their data. To switch it off later, go to Settings › Apps › App Store.
2. Remove downloads you can get again
Offline music, podcast episodes, streaming downloads and the Safari Reading List take real space and come back in seconds when you are on Wi-Fi.
- Music, Podcasts, TV: tap the app in iPhone Storage and swipe left on downloaded items, or remove downloads inside the app.
- Streaming apps (Netflix, Spotify and others): use the app’s own Downloads screen.
- Safari: in iPhone Storage, tap Safari, then swipe left on Offline Reading List.
3. Move or remove large videos
Videos are usually the biggest single files on a phone. A few minutes of 4K video can take more space than hundreds of photos.
- In Photos, open Collections › Media Types › Videos.
- Pick the longest clips you no longer need on the phone.
- Copy them to a computer, drive or second cloud service, and play the copy to check it works. The large video guide covers formats and size limits.
- Delete them from the phone.
- Open Recently Deleted and remove them there too. Photos keeps deleted items for up to 30 days, and they still use space until then.
If you use iCloud Photos, deleting a video on the phone deletes it from iCloud and your other devices. Make the outside copy first.
4. Clear large message attachments
- In iPhone Storage, tap Messages.
- Tap Review Large Attachments.
- Swipe left on anything you do not need, or tap Edit to select several.
You can also limit how long texts stay on the phone: Settings › Apps › Messages › Keep Messages (on older iOS versions, Settings › Messages). Choosing 30 days or 1 year permanently removes older messages and their attachments, so save any receipts, photos or conversations you want first. If WhatsApp is your big messaging app, use the WhatsApp storage guide.
5. Offload or delete apps you rarely use
Tap an app in iPhone Storage and choose one of two buttons:
| Button | What leaves the phone | What stays | Good for |
|---|---|---|---|
| Offload App | The app itself | Its documents and data, plus its Home Screen icon | Apps you use a few times a year |
| Delete App | The app and all its local data | Only what the app synced to an account | Apps you are done with |
Before deleting, check the app holds nothing you need, such as authenticator codes, offline tickets or game progress that is not synced. Deleting an app does not cancel its subscription. Use the subscription guide for that, and the app review guide for a fuller pass.
6. Let iCloud Photos keep the full-size originals
If you pay for enough iCloud space, the phone can keep small versions of your photos and fetch the originals when you open them. Apple turns this on by default when you use iCloud Photos, but check it:
- Go to Settings › your name › iCloud › Photos.
- Make sure Sync this iPhone is on.
- On iOS 27, tap iPhone Storage.
- Choose Optimize iPhone Storage.
This frees phone space only if your iCloud plan can hold the whole library. Clearing duplicate photos and old screenshots helps both limits at once.
If System Data is the biggest category
System Data often grows for a while after a major iOS update, while the phone rebuilds its search index and caches. Restart the phone, leave it on Wi-Fi and charging overnight, and install any newer iOS update. If it is still the largest category after that, read the System Data guide. Save a factory reset for last: it takes hours, needs a working backup and is the option most likely to cost you data.
Check that it worked
- Go back to Settings › General › iPhone Storage and let the bar recalculate. Freed space can take a few minutes to appear.
- Empty Recently Deleted in Photos if you removed photos or videos.
- Open one or two of the files you copied elsewhere to confirm they play or open.
- Note what filled the phone. If videos were the cause, a monthly export habit will stop the warning from coming back.
When cleanup is not enough
If the phone fills again within weeks, the problem is capacity. Three honest options remain: move your photo and video archive to a computer or drive on a schedule, pay for an iCloud plan big enough for Optimize iPhone Storage to work, or choose more storage on your next phone. The phone storage overview compares them.
Steps checked against Apple Support in November 2026 (iOS 26 and iOS 27). Menu names can shift slightly between iOS versions.
Sources
- Apple Support: How to check the storage on your iPhone and iPad
- Apple Support: Manage your photo and video storage
