Start by opening the device storage screen to see your apps listed by size: that list tells you where the space went (Solution 1). On most full iPhones the bulk sits in three places, and none of them is the photo library: large apps you barely use, videos and music downloaded from streaming services, and years of attachments piled up in Messages (Solutions 2, 3 and 4). Offloading an app frees the program's space and keeps your data, so nothing is lost. If you use iCloud Photos, Solution 5 keeps the full-size versions in the cloud and leaves only light ones on the device, without deleting a single image. Leave Solution 8 for last, when System Data is bloated with no explanation.
What causes this problem
- Heavy apps installed years ago and opened once or twice, taking several gigabytes each.
- Videos, shows, music and podcasts downloaded for offline use and never removed afterwards.
- Messages and WhatsApp attachments piling up: photos, voice notes and videos from old conversations.
- Photos and videos shot at high resolution and kept at full size on the device.
- Items in the Recently Deleted album, which keep taking up space for up to 30 days.
- Cache and temporary files added up in the System Data line, which grows quietly.
- Confirm the problem is device space and not iCloud space. If the warning mentions backup or syncing, the subject is the cloud, and this guide is not the right path.
- Leave the iPhone charging and on Wi-Fi. Offloading apps and optimising photos need a connection and can take a while.
- Know the difference between Offload App and Delete App: offloading removes only the program and keeps your data; deleting takes everything with it.
- Write down how much free space you have right now, on the storage screen. That way you can measure the effect of each step instead of guessing.
- If you plan to use Solution 5, check that iCloud Photos is on and that your account has room. Without that, optimisation will not work.
Solutions, in the order to try them
1Find out where the space actually went
Before deleting anything, look at the list the iPhone builds for you. It shows a coloured bar by category and, underneath, every app in order of size with the date it was last used. There are almost always two or three surprises at the top, and that is where the effort pays off. This screen also offers ready-made recommendations, such as reviewing large attachments.
- Open Settings, go to General and tap iPhone Storage.
- Wait a few seconds for the coloured bar to finish calculating.
- Read the app list top to bottom and note each one's size and last-used date.
- Write down the three or four biggest. Those are the ones that will free real space in the next solutions.
- Tap each recommendation shown at the top of the screen and check how much it promises to free before applying it.
2Offload the large apps you barely use
Offloading removes the program and keeps all of its documents and data on the device. The icon stays on the home screen with a small cloud beside it, and one tap reinstalls the app with everything where it was. It is the safest way to recover several gigabytes, because nothing of yours is deleted. It pays off mostly with games and editing apps, the biggest items on the list.
- On the iPhone Storage screen, tap a large app that has gone months without use.
- Choose Offload App and confirm. Repeat with the others on your list.
- To automate it, go back to Settings, open App Store and turn on the option to offload unused apps.
- If an app shows far more data than app size, the weight is in the content saved inside it, and offloading will not help: open the app and clear its downloads there.
3Delete videos and music downloaded from streaming apps
Downloading an episode to watch on a plane is easy to forget, and every saved season eats gigabytes. These files do not show in the photo library: they hide inside each app and count as its data. Deleting them costs nothing, because the content becomes available over the internet again whenever you want it.
- Open each video, music or podcast app that showed up large in the Solution 1 list.
- Look for the downloads or offline content section, inside the app's profile or library.
- Delete what you have already watched or listened to, starting with the videos.
- In podcast apps, look for the setting that removes episodes automatically once played.
- Go back to the storage screen and check each app's new size to see how much it returned.
4Clean up Messages: heavy attachments and old history
Conversations keep every photo, voice note and video ever received, and that is the hidden champion of storage use on iPhones owned for years. You can work on two fronts: remove the biggest attachments one by one, without losing the text of the conversations, and set a limit so old messages clear out by themselves. Deleting history is permanent, so check beforehand whether there is anything you want to keep.
- In Settings, open General, go to iPhone Storage and tap Messages.
- Use the photos, videos and attachments categories to see the largest files and delete the ones you do not need.
- To limit the history, go back to Settings, open Messages and look for the option that sets how long to keep messages. Choosing 1 year instead of forever frees a lot of space.
- In WhatsApp and other messengers, find the storage section inside the app's own settings and delete the large files there.
- Before confirming any history deletion, save to your photo library the pictures and documents from those chats that you want to keep.
5Keep light photos on the device and full-size ones in the cloud
This is the fix for anyone with thousands of photos who does not want to delete any. With iCloud Photos on, the iPhone keeps reduced versions on the device and stores the originals in your account. You still see everything in the Photos app, in the same order, and the original downloads on demand when you open or edit an image. This needs available iCloud space and a connection to work well.
- Open Settings and go to Photos.
- Confirm that syncing with iCloud is on.
- Choose the option to optimise iPhone storage rather than download and keep originals.
- Leave the device charging on Wi-Fi for a few hours: space is released gradually as the iPhone uploads the originals.
- If you do not use iCloud, the free alternative is to copy the photos to a computer over cable and only then delete them from the device.
6Empty the recently deleted albums
When you delete a photo it leaves the library but stays for about 30 days in a recovery album, taking exactly the same space as before. The same logic applies to files and notes. Emptying those albums is the fastest way to turn deletions you already made into real free space.
- Open the Photos app and go to the album list at the bottom of the screen.
- Open the recently deleted album, unlock it if asked and use the option to delete everything.
- Repeat in the Files app, which has a recently deleted folder on its browse screen.
- Do the same in the Notes app's deleted folder and in your mail app's trash, if you use one.
- Check the storage screen afterwards: the space usually shows up within a few minutes.
7Clear Safari and the downloads folder
The browser stores cache, images and pages to load faster, and that grows over time. Alongside it, the downloads folder collects PDFs, bills and files you opened once and forgot. Clearing Safari data signs you out of sites you were logged into, so have your passwords at hand.
- In Settings, open Safari and choose the option to clear history and website data.
- Still in Safari, go into the advanced settings and review the data stored per site, deleting the largest ones.
- Open the Files app and look for the Downloads folder inside the iPhone storage.
- Delete the files you no longer need and then empty the recently deleted folder.
8If System Data is huge, restart and reassess
The grey band called System Data bundles the cache, logs and temporary files iOS uses. A few gigabytes there is normal, but when it passes ten it is usually stuck cache that was never released. There is no official button to clear that category, which is why this solution comes last. A restart resolves a good share of cases and carries no risk at all.
- Switch the iPhone off completely, wait half a minute and turn it back on.
- Return to the storage screen and see whether the grey band shrank after a few hours of normal use.
- If it stays bloated, apply Solutions 3 and 4: streaming and messaging leave the most cache behind.
- As a last resort, make a full backup and restore the device from it. That rebuilds the system and returns the stuck space, but it takes hours and should only be done with the backup confirmed.
- Never install apps that promise to clean the iPhone from the outside: they have no access to that part of the system.
Applies to
| System | Status |
|---|---|
| iPhone on iOS 16, 17 and 18 | Confirmed |
| Newer iOS releases | Some items move around; use the search bar at the top of Settings to go straight there |
| iPad (iPadOS) | The path is the same, listed as iPad Storage |
| iOS 15 or older | The screens look different, but offloading apps and clearing attachments work the same |
Menu names can change slightly between versions. If a step above does not match what you see on screen, the official support page from the manufacturer has the most current wording for your version.
Frequently asked questions
Last checked: Oct 4, 2026 · We review this guide whenever the manufacturer changes the process.