You copy a clip from your iPhone to a computer or send it to a friend, and the .MOV file won't open, plays sound with no picture, or a website refuses the upload. Here's why it happens and how to fix it.
In short
- iPhones record video as MOV files, compressed with HEVC (H.265) to save space.
- Many Windows PCs can't play HEVC without an extra extension.
- The fixes: record in Most Compatible, let the iPhone convert when sharing, or convert MOV to MP4 in your browser.
What MOV is
MOV is Apple's QuickTime file format. Apple explains that the QuickTime File Format is the basis of the MPEG-4 standard from the International Organization for Standardization (ISO). MOV and MP4 files are therefore structured alike, but they are different file types — which is why some programs and websites take MP4 only.
Why some devices can't play it
The real problem is usually not the MOV extension but the picture compression inside. Apple says that since iOS 11 its devices use HEIF for photos and HEVC, also known as H.265, for video, which compress better than H.264 and use less storage.
Microsoft, however, says Windows needs the HEVC Video Extensions from the Microsoft Store (a small fee) to play HEVC video, so a PC without them may show nothing, or only play the sound.
Fix 1: make the iPhone record in a format everything plays
Apple's instructions: open Settings > Camera > Formats and choose Most Compatible. The camera then records photos as JPEG and video as H.264, which plays almost everywhere.
The downside is bigger files; to go back to the space-saving format, choose High Efficiency.
Fix 2: let the iPhone convert when you share
Apple says that when you share through AirDrop, Messages or email to a device that doesn't support HEVC, the video may be sent in a more compatible format such as H.264, and videos imported to a computer over USB may be converted to H.264 too. To stop that, go to Settings > Apps > Photos and choose Keep Originals.
Fix 3: convert MOV to MP4 in your browser, without uploading
If you already have the .MOV file, use MOV to MP4:
- Choose or drop the MOV file (up to 2 GB).
- Convert to MP4.
- Download the MP4.
The tool adapts to the picture inside the file:
- If it's already H.264, the original picture is copied into an MP4 — quick, with unchanged quality.
- If it's HEVC (most iPhone videos), it's re-encoded as H.264 so it plays almost everywhere; this takes longer.
Your video is never uploaded; everything happens in your browser. You need a recent browser such as Chrome or Edge, and if yours can't decode the video, the page tells you.
What next
- Too big to send by LINE or email? Compress the video.
- Only need the sound? Use MOV to MP3.
- Want a short animation? Try MOV to GIF.
Note
This article is based on Apple's support pages, Apple Developer's QuickTime File Format documentation and Microsoft's support page, read on 29 September 2026. Menu names and extension prices can differ by version and country.
