1MOV, MP4 and HEVC: three different things
The confusion comes from three nested notions. MOV is a container: a box, exactly like MKV or MP4. The codec is what it holds: H.264, H.265, ProRes. And the .mov extension says nothing about the codec, since any of the three can live inside it.
That is why two .mov files can meet opposite fates. One from a camera or a recent iPhone generally holds H.264 or H.265; one exported from Final Cut Pro often holds ProRes, a professional format designed for editing, never for browser playback.
2The iPhone-on-Windows case
Since the iPhone 7, Apple records in HEVC, also called H.265, inside a MOV container. The gain is real — roughly half the size of an equivalent H.264 video — but compatibility on a Windows computer is far less so.
Windows does not decode H.265 for free: it requires a paid Microsoft Store extension, plus a processor with the right hardware decoding. Most free video players handle H.265 without trouble. The browser sits in between: Edge usually copes, Chrome depends on the hardware, and Safari — on a Mac — handles it with no issue.
3What a browser can genuinely play
| Codec inside the MOV | Browser playback |
|---|---|
| H.264 (most common) | yes — Chrome, Edge, Safari, Firefox depending on the system |
| H.265 / HEVC (recent iPhone) | partial — Safari and Edge, often not Chrome |
| ProRes (Final Cut Pro) | no — no browser at all |
| AAC (standard audio) | yes |
| Uncompressed PCM audio | no — rare in MOV |
4Opening a folder of MOV files in Pixora Viewer
The viewer explicitly accepts MOV in its video format list. It performs no transcoding: the file goes to the browser engine, which guarantees instant playback and no upload whatsoever.
You can mix MOV and MP4 videos with still images in the same folder: the slideshow runs through them in the natural alphabetical order of the file names. A video the browser cannot decode is reported and skipped automatically, which lets you spot the genuinely problematic files in a holiday folder straight away.
- Open the viewer.
- Select the folder containing your MOV videos.
- The slideshow starts. Videos play through to the end, then the next file takes over.
- The progress bar shows the real position within the video, and the total duration as soon as the file has loaded.
5If your MOV will not open, what next?
- Try another browser first. With an iPhone MOV, switching from Chrome to Edge solves the problem in most cases, because Edge relies on the system decoders.
- Check whether it is ProRes. A file exported from Final Cut Pro or a professional camera will play in no browser, whatever you try. It has to be re-encoded to H.264.
- Convert to MP4 in H.264 if the file is to be shared. It is the most universal format there is: it plays on every computer, every phone and every recent television.
- Change your iPhone recording settings if the problem keeps coming back: switching from HEVC to H.264 removes the difficulty at the source.
6Frequently asked questions
Why will my iPhone video not open on my PC?
Since the iPhone 7, videos are recorded in H.265 (HEVC), a codec Windows cannot decode without a paid extension and a compatible processor. The file is not damaged: your computer simply cannot read it.
Is MOV better than MP4?
They are technically very close — both descend from the same base format. MOV is favoured in the Apple ecosystem and professional editing, MP4 everywhere else. For distribution, MP4 is the safe choice.
What is ProRes, and why will it not play?
ProRes is a professional Apple codec designed to retain maximum quality during editing. Its files are large and require specialised decoders that browsers do not include. It must be converted to H.264 to be viewed on the web.
Can I mix MOV, MP4 and photos in one slideshow?
Yes. The viewer accepts the main image and video formats within a single slideshow and presents them in the natural alphabetical order of their names.
See your MOV videos in the browser
Open the folder and start playback. Unplayable files are reported, not quietly ignored.
Open the viewer