How to copy iPhone videos to a NAS without compression

By Isaac Griffiths, developer of SMBDrop · 11 October 2026

iPhone video files are big, and plenty of the usual ways of moving them quietly make them smaller. A 4K clip sent through a messaging app can arrive looking fine on a phone screen and fall apart on a TV. If you're archiving family videos or footage you'll edit later, you want the file the camera recorded, byte for byte.

This guide covers where compression creeps in, how to copy originals to a NAS or shared folder, and how to check what you ended up with.

Disclosure: I make SMBDrop, which is one of the methods below. The checks at the end work whatever you use.

How big are iPhone videos?

Bigger than most people expect. Settings → Camera → Record Video shows the approximate size of one minute for each resolution and frame rate on your iPhone; 4K at 60 fps in HEVC is several hundred megabytes a minute. ProRes, on Pro models, is far larger: around 6 GB for a minute of 4K, according to Apple's figures at launch. On 128 GB Pro models, Apple limits ProRes to lower resolutions for that reason, and recent Pro models can record ProRes straight to an external USB-C drive.

That size is exactly why so many services compress video before sending it.

Where iPhone videos get compressed

Messages. Large videos sent in Messages can be sent as a smaller version, especially to non-Apple phones over SMS/MMS or RCS. Fine for sharing, not for archiving.
WhatsApp and other messaging apps. These re-encode video to save bandwidth, even with "HD" quality turned on. Sending the video as a document rather than as media usually keeps the original file, if you must use one.
iCloud Shared Albums. Shared albums store reduced-resolution copies of videos, not the originals.
Save to Files with the wrong format. When you share from Photos, the share sheet's Options include a format choice. Most Compatible converts HEVC video to H.264, which re-encodes it. Choose Current to keep the original.
Transfer to Mac or PC. With a cable, the default Automatic option in Settings → Apps → Photos → Transfer to Mac or PC on iOS 18 and later (Settings → Photos → Transfer to Mac or PC on iOS 17) may convert to compatible formats. Choose Keep Originals.
Optimize iPhone Storage. With iCloud Photos on, older videos on the phone may be lower-resolution versions; the original is in iCloud and has to download before any app can copy it.

AirDrop between Apple devices is generally a good way to move an original, though what the receiving Mac does with it (Photos library or Downloads) depends on what you send. It's fine for a handful of clips; for a library's worth, a NAS copy is easier to manage.

Method 1: Send originals over SMB

If your NAS or computer shares a folder over SMB, an app that reads your photo library directly can copy the original video files without going through the share sheet. With SMBDrop:

Add your share in Settings: the server address and your sign-in, then Find Shares to pick the folder, then Test Connection. Setup guides: Synology, QNAP, UGREEN, Unraid and TrueNAS, Windows, Mac.
Select the videos and tap Send.
Keep the iPhone on Wi-Fi and, for big batches, on a charger. You can leave the app; anything interrupted waits in the retry queue so you can resume rather than start again.

SMBDrop sends the original file from your library, so HEVC stays HEVC, ProRes stays ProRes, and HDR and metadata are kept. Nothing is re-encoded.

Method 2: Import with a cable

Set Transfer to Mac or PC to Keep Originals, connect the iPhone, and import with Image Capture or Photos on a Mac, or the Photos app on Windows. Then copy the files to your NAS. It's free and it's fast over USB-C, which matters for ProRes. It's also manual, and you'll need room on the computer.

Method 3: Your NAS maker's app

Synology Photos, QNAP's Qfile Pro and the UGREEN NAS app all back up videos. Check their settings for any conversion options, then verify a few files as below.

How to check a video wasn't compressed

Compare the size. In Photos, swipe up on the video to see its details, including size and format. The file on the NAS should be essentially the same size. A big drop means it was re-encoded.
Check the format. On a Mac, QuickTime Player's Window → Show Movie Inspector shows the codec, resolution and frame rate. On any computer, the free MediaInfo app shows the codec, bitrate, HDR format and recording date.
Watch the hard parts. Fast motion, dark scenes and fine detail are where compression shows first.
For certainty, compare checksums of two copies, for example the cable import and the NAS copy: shasum -a 256 IMG_1234.MOV on a Mac or Get-FileHash IMG_1234.MOV in Windows PowerShell.

Practical tips for big transfers

Use 5 GHz or 6 GHz Wi-Fi near the router, or a wired connection on the NAS side. Wi-Fi is usually the bottleneck, not the NAS.
Turn off Low Power Mode during a big send; it limits background activity.
Send in batches by date, so a failure is easy to retry and to verify.
Make sure the destination has room: an afternoon of ProRes can be hundreds of gigabytes.

FAQ

Does AirDrop compress iPhone videos?

Between Apple devices, AirDrop generally sends the original file. Check the Options at the top of the share sheet, and verify the size on the receiving device if it matters.

Does sending a video in Messages reduce its quality?

It can. Large videos may be sent as smaller versions, especially to non-Apple phones. Don't use Messages or other messaging apps to archive videos.

How do I copy ProRes video from an iPhone to a NAS?

Use a method that copies the original file: an SMB app that reads your library directly, such as SMBDrop, or a cable import with Transfer to Mac or PC set to Keep Originals, then copy to the NAS. Expect around 6 GB per minute of 4K ProRes.

How can I tell if a video was compressed?

Compare the file size with what Photos shows for the original, check the codec and bitrate in QuickTime's Movie Inspector or MediaInfo, and compare checksums if you have two copies.

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