If your iPhone can already copy photos to a USB drive for free, it is fair to ask what a dedicated app is for.
This is a direct comparison of the two, written after going through the VaultDrive source. Every claim about what the app does is based on what the code actually does, which matters, because a lot of the comparison material floating around overstates it in both directions.
The short answer is that Save to Files is a genuinely good tool for a small job, and the differences only start to matter at the scale of a whole photo library. Here is where that line sits.
For the mechanics of connecting a drive in the first place — adapters, formatting, powered hubs — see how to back up iPhone photos to a USB drive without a computer.
When the Files app is the right tool
Worth saying plainly, because it is often true.
If you want to move a few dozen photos, a handful of documents, or the videos from one afternoon, open Photos, tap Select, choose the items, tap Share, pick Save to Files, and choose the drive. It is free, built into iOS, needs no additional software, and it works.
For a one-off transfer, this is the correct answer and a dedicated app is overkill. Nothing below argues otherwise.
Where it starts to break down
The problems are not bugs in the Files app. They are consequences of it being a general file mover rather than a backup tool.
Your originals may not be on the phone
This is the big one on iOS, and it catches almost everybody.
If Optimize iPhone Storage is enabled — and if you use iCloud Photos and have ever been short on space, it very likely is — your phone holds screen-sized previews while the full-resolution originals live in iCloud. A preview looks perfect on the display and is not the file you want in an archive.
So a "backup" made without dealing with this can consist substantially of previews rather than originals, which is the worst kind of failure: it looks complete and is not.
VaultDrive treats this as a first-class case. iCloud downloading is on by default, and originals are fetched before copying. Anything that could not be retrieved is reported as "In iCloud — not on this phone" in the summary rather than being silently counted as done.
Selection is manual, and there is no memory
Selecting several thousand photos by dragging across a grid is unpleasant and error-prone. Worse, the Files app has no notion of what you copied last time. Next month you either re-copy everything or try to remember where you stopped.
VaultDrive tracks every item in a local database keyed to the photo library's own asset identifiers, so a later run copies only what is new. That incremental behaviour is the paid tier's main practical benefit: the first backup is long, and every one after it is short.
One failure should not end the run
A long transfer will encounter something awkward — a file that cannot be read, an item still stuck in iCloud, a video too large for the drive's format.
In VaultDrive, a per-item failure is classified, recorded against that item, counted, and the loop moves to the next file. The failure categories in the code are specific: in iCloud — not on this phone, waiting for Wi-Fi, drive ran out of space, couldn't read from photo library, copy verification failed, couldn't export the file, over the free plan limit, and other. The summary groups failures by cause instead of showing a bare number, and failed items can be retried.
There is exactly one deliberate exception: if the drive runs out of space, the session stops. Continuing would achieve nothing.
Nothing checks that the copy is real
A file copy that silently truncates still leaves a file on the drive. It will even produce a thumbnail.
After each copy, VaultDrive confirms the file exists at the destination and that its size matches the source, and it can compare a SHA-256 hash of the copy against the original. Anything failing either check is marked failed rather than counted as backed up.
This is the difference between a copy and a backup, and it is the step that manual transfers never include.
What the drive actually looks like afterwards
This is worth being precise about, because it is commonly described inaccurately.
A manual Save to Files puts whatever you selected into whatever folder you picked. Organizing it is your job.
VaultDrive writes a fixed, readable hierarchy:
USB Drive/
└── VaultDriveBackup/
└── [Your-iPhone-Name]/
├── Italy 2025/IMG_3021.HEIC ← your album, as a folder
│ IMG_3021.mov ← Live Photo pair, same base name
├── Family/VID_0082.MOV
├── Screenshots/…
├── Files/[original folder hierarchy]/…
└── Metadata/backup_index.json
Your albums become the folders. A photo in an album called "Italy 2025" lands in a folder called Italy 2025. Screenshots always go to Screenshots, and anything not in a user album falls back to a folder named for its media type. Documents picked from the Files app keep their original folder hierarchy under Files/.
The album a photo came from is recorded during the scan, which is what makes this work for Smart Albums too — those are invisible to the PhotoKit API that would otherwise be used to ask which album an asset belongs to.
There is also a date-based layout in the code — media type, then year, then month — but it is the fallback, not what you get. Mirroring is the default and the setting to turn it off is not currently exposed.
Two details that matter for fidelity. Live Photos are kept as a pair: the still and its paired video are copied with the same base name, rather than being split into unrelated files. And files are copied byte for byte, so HEIC, ProRAW, ProRes, 4K and Cinematic arrive without re-encoding.
Each device gets its own folder, so several phones can share one drive.
Network control, and an honest note on background behaviour
Because iCloud downloads can pull a lot of data, VaultDrive defaults to Download over Wi-Fi only. Turn it off and it will use cellular too. If you start a backup on cellular with the setting on, iCloud-only items are skipped with the reason waiting for Wi-Fi and picked up automatically on the next run over Wi-Fi.
Now the part usually overstated, including in material I was given while researching this: VaultDrive does not run backups in the background on iOS, and no app can. iOS suspends apps shortly after they leave the foreground.
What actually happens is that the backup pauses when you leave the app and resumes automatically when you return, from the position it recorded, with the session never marked interrupted so it reads as continuous. Files already copied stay copied.
Separately, the app uses a background processing task to scan for new photos while you are not using it, so it can notify you that new items are ready — that is detection, not copying.
The practical difference from a manual transfer is not that one runs in the background and the other does not. It is that an interruption costs you a pause instead of the whole transfer.
Drive format, caught before you waste an hour
FAT32 cannot store a single file larger than 4 GB. Most flash drives ship formatted FAT32, and a long 4K or ProRes video exceeds that easily.
Manually, you discover this when a video refuses to copy. VaultDrive detects the drive's filesystem when you choose it and flags FAT32 up front, alongside an in-app guide comparing exFAT, FAT32 and APFS. exFAT is the recommendation, for the same reasons it always is.
Side by side
| Save to Files | VaultDrive | |
|---|---|---|
| Cost | Free, built in | Free to 200 files / 2 GB per run; Pro is one-time |
| Good for | A small batch | A whole library, repeatedly |
| Selection | Manual | Whole library or chosen albums |
| iCloud originals | Your problem | Downloaded first, reported if unavailable |
| Knows what it copied | No | Yes, tracked per item |
| Repeat backups | Copy everything again | Only new or changed files |
| One file fails | You investigate | Classified, logged, run continues |
| Verifies the copy | No | Exists + size, optional SHA-256 |
| Live Photos | May split | Kept paired |
| On the drive | Where you put it | Your albums, as folders |
| Warns about FAT32 | No | Yes, before backup |
| Interrupted | Generally restart | Pauses, resumes where it stopped |
So which should you use?
Use the Files app for a small, one-off transfer. It is free and already on your phone, and there is no reason to add software to move forty photos.
Consider a dedicated app when you are backing up a whole library, when you intend to do it repeatedly, when Optimize iPhone Storage is on, or when you plan to delete the originals afterwards — because that last case is the one where an unverified copy becomes a real loss.
The free tier covers 200 files or 2 GB per run, which is enough to watch how it behaves on your own library before deciding.
Whichever route you take, the rule from how to back up iPhone photos to a USB drive still applies: verify the copy before you delete anything from the phone. And if iCloud Photos is on, deleting from the phone removes the photo everywhere, which is the difference between a sync and a backup.
Frequently Asked Questions
Can the iPhone Files app copy photos to a USB drive on its own?
Yes. Select photos in the Photos app, tap Share, choose Save to Files, and pick the connected drive. It is free, built in, and completely adequate for a small batch. The difficulties appear at library scale, where manual selection, no record of what was already copied, and no handling of iCloud-only originals start to matter.
Why do some photos fail to copy from an iPhone to a USB drive?
The most common cause is Optimize iPhone Storage. When it is on, your phone holds smaller previews while the full-resolution originals stay in iCloud, and the original has to be downloaded before it can be copied. The second most common cause is drive format: FAT32 cannot store any single file larger than 4 GB, so long 4K and ProRes videos fail on a FAT32 drive.
Does VaultDrive keep running when I leave the app on iPhone?
No, and no iPhone app can copy to a USB drive while suspended. iOS suspends apps shortly after they go to the background, so the backup pauses. The difference is what happens next: VaultDrive records its position, and when you return to the app it resumes from where it stopped rather than starting over or losing the files already copied.
How does VaultDrive organize photos on the USB drive?
It mirrors your albums. Under VaultDriveBackup and a folder named for your device, each photo lands in a folder named after the album it came from, so an album called Italy 2025 becomes a folder called Italy 2025. Screenshots go to a Screenshots folder, anything not in an album falls back to a folder named for its media type, and documents keep their original folder hierarchy under Files.
What happens if one file fails partway through a backup?
VaultDrive records the reason against that item, counts it, and continues with the next file, so a single unreadable or iCloud-only item does not end the run. The summary groups failures by cause, such as in iCloud, couldn't read file, or verification failed, and failed items can be retried. The one deliberate exception is the drive running out of space, which stops the session because continuing would be pointless.
Does VaultDrive verify that files copied correctly?
Yes. After each copy it confirms the file exists at the destination and that its size matches the source, and it can additionally compare a SHA-256 hash of the copy against the original. A file that fails either check is treated as failed rather than counted as backed up, which is the difference between a copy and a verified backup.
The short version
The Files app is a file mover. It moves files, correctly, and for a small job that is all you need.
A backup tool is a different thing. It has to know what it already copied, deal with originals that live in iCloud rather than on the phone, survive an interruption without losing its place, keep going when one file misbehaves, check that what landed on the drive is what left the phone, and put the result somewhere you can still navigate in five years.
Below a few hundred files, that machinery is unnecessary. Above it, doing the job by hand is how people end up with a drive that looks like a backup and is not.
The Android comparison is here.