The file says .MOV. That's only half the story
The .MOV extension only describes the container — the box the video sits in,
not what's actually inside it. Since the iPhone 7, the video inside that box has by default
been encoded with HEVC (H.265), not the older H.264 that most cameras and phones used for
the previous decade. Same box, different contents — which is why a file can look completely
normal in Finder and still refuse to open somewhere else.
Why Apple switched
HEVC compresses roughly twice as efficiently as H.264 at the same visual quality, which is the entire reason it exists on a phone: a 4K video that would eat 2GB as H.264 takes about 1GB as HEVC. Photos got the same treatment with HEIC, which does to stills what HEVC does to video. Both trade a smaller file for more decoding work, which modern phone and Mac chips handle without breaking a sweat — older Windows PCs and some editing software sometimes can't.
Where compatibility actually breaks
- Any modern Mac plays and edits HEVC natively — Photos, QuickTime, Final Cut and DaVinci Resolve all handle it without conversion.
- Windows 10/11 can play HEVC, but usually needs the HEVC extension installed from the Microsoft Store first — it's not always there by default.
- Older editing software, some web upload forms and a handful of Android phones still expect plain H.264/JPEG and will reject or mishandle HEVC/HEIC.
The setting that avoids all of this
Settings → Camera → Formats has two options: High Efficiency (HEVC/HEIC, the default) and Most Compatible (H.264/JPEG). Switching to Most Compatible before a shoot where footage needs to go straight into an older pipeline, or onto a machine you don't control, avoids the conversion question entirely — at the cost of roughly double the file size for the same footage.
Automatic vs Keep Originals: Settings → Photos has a separate "Transfer to Mac or PC" toggle. "Automatic" quietly converts HEIC/HEVC to JPEG/H.264 during transfer wherever the receiving app doesn't declare HEVC support; "Keep Originals" always hands over the file exactly as shot. If a file ever comes off the phone smaller or different than expected, this setting is usually why.
ProRes: a separate, bigger jump
On Pro models that support it, Apple ProRes is a different tier entirely — a professional-grade codec meant for grading, not compression. It's large enough that recording 4K ProRes on-device is capped by the phone's own storage and speed; recording directly to an external SSD over USB-C removes that ceiling. It's overkill for casual clips, but for anyone using the iPhone as a genuine B-camera in a color-managed pipeline, it's the format that behaves like the rest of the footage instead of standing out from it.