SweeperX
How to find the largest files on your iPhone
The iPhone Storage screen
Everything starts at Settings → General → iPhone Storage. Give it a minute; the bar chart at the top calculates in the background and is wrong until it settles.
Below the chart is a list of every app, sorted largest first. That order is the single most useful piece of information your phone will give you about storage, and most people never scroll it. iOS also puts Recommendations at the top — offloading unused apps, reviewing large attachments — which are worth reading even if you decline them.
Two things this screen does not tell you: which individual photo or video is largest, and what is inside any app's Documents & Data. Both need different tools.
Apps versus their Documents & Data
Tap any app in that list and you get two numbers:
- App Size — the program itself. Re-downloadable at any time.
- Documents & Data — everything the app has accumulated: caches, downloads, offline content, message history.
A podcast app at 80 MB with 14 GB of Documents & Data is not a large app; it is a large pile of episodes. The distinction determines the fix:
- Offload App removes the app and keeps its data, so reinstalling restores your state. Useful for a big app you use twice a year. Useless when the data is the problem.
- Delete App removes both. This is the only reliable way to clear an app's cache, and it is worth saying plainly: no third-party app can do this for you. iOS does not permit one app to reach into another's storage. Any cleaner offering to “clear junk files” across your apps is describing something the operating system forbids.
Before deleting, check inside the app first. Most podcast, music and video apps have their own “downloads” screen where you can remove content without losing your account or settings.
Sorting Files by size
Everything that is not a photo, a message or app-internal lives in the Files app under On My iPhone, and almost nobody looks there.
- Open Files and tap Browse.
- Choose On My iPhone.
- Switch to list view, then use the sort control and pick Size.
Now the biggest thing is at the top. Typical finds: a zip you extracted and never deleted, offline maps, a PDF scan at absurd resolution, exports from an editing app, a video someone AirDropped you a year ago.
One warning that matters. Files deleted here do not go to Recently Deleted the way photos do — the Files app has a Recently Deleted folder for iCloud Drive, but items removed from local On My iPhone storage are generally gone immediately. Look before you delete; there is no 30-day grace period standing behind you.
The videos Photos will not rank
Here is a real gap in iOS: the Photos app cannot sort your library by file size. There is no setting for it, and the largest video on your phone is not findable through Photos by any direct route.
What you can do is narrow the field. Albums → Media Types → Videos shows every video in one place, and duration is a fair proxy for size when everything was shot at the same setting. Sorting your instinct by length will usually find the four clips that matter.
For context on what those clips cost: 4K at 60 fps runs to roughly 400 MB per minute, so a single three-minute clip outweighs a thousand photos. The full table, and what to do about it, is here.
This gap is the clearest case for a tool that can do what Photos will not: rank your library by what each item actually costs.
Messages, the quiet one
Messages is frequently among the top three entries on the iPhone Storage list and almost never the one people suspect. Every photo, video, voice note and GIF anyone has ever sent you is kept by default, forever.
Two fixes, both free:
- Settings → Messages → Keep Messages, set to 1 Year or 30 Days instead of Forever. iOS offers to delete what is already older than that, and it is usually a large number.
- Settings → General → iPhone Storage → Messages → Review Large Attachments, which lists the biggest items across every conversation, sorted by size.
Deleting a conversation deletes it from this device. If Messages in iCloud is on, it deletes from all of them.
System Data, and why nothing can clear it
At the bottom of the storage chart is a category called System Data, formerly “Other”. It can be a few gigabytes or, occasionally and infuriatingly, twenty.
It holds caches, logs, streamed media buffers, Siri voices, font files and temporary work files that belong to iOS itself. No app can delete any of it. There is no setting, no button, and no third-party tool with special access — the sandbox that prevents apps from reading each other's data prevents this too.
What actually works, in order of effort: restart the phone, which clears a surprising amount of transient cache. Delete and reinstall the apps that stream heavily, because their buffers are often counted here. Update iOS, since a pending update sits in this category until it installs. And as a last resort, back up, erase and restore, which rebuilds the whole thing.
An app advertising that it will reduce your System Data is advertising something that cannot happen. It is a useful test of who is being straight with you.
A sensible order of attack
- Read the storage screen and find out what your actual problem is. It is rarely what you assumed.
- Large videos first. Best ratio of space recovered to decisions made, by a wide margin.
- Messages attachments. Free, fast, and nobody misses them.
- Files, sorted by size. A five-minute job that often finds gigabytes, with no emotional weight attached.
- Then the photo library — duplicates, similar frames, screenshots. Most decisions, so leave it until you know whether you still need to.
- Empty Recently Deleted when you are confident, or wait 30 days for iOS to do it.
If the manual pass is enough, you are done, and no purchase improves on free. SweeperX exists for the part iOS makes tedious: it scans “On My iPhone” sorted by size, lets you add any folder of your own to the scan, and ranks your photo library by what each item actually costs — the sort Photos will not give you. It stages everything for review, warns you that Files deletions are immediate rather than recoverable, and runs entirely on the device.
Next: How to Clean Up Duplicate Contacts on iPhone — no storage saved, considerable annoyance removed.