Why your iPhone video won't play on Windows

You copied a video off an iPhone, opened it on a Windows PC, and got a black screen, sound with no picture, or an error about an unsupported format. Almost every search result will tell you to convert the .mov to .mp4. That advice is usually wrong — and this page explains why, including why our own MOV to MP4 converter will not fix it either.

A video file is two things, and only one of them is the problem

A video file has a container and a codec. The container is the wrapper — .mov, .mp4, .mkv — holding the tracks, the timing and the metadata. The codec is the compression format the picture itself is stored in, inside that wrapper: H.264, HEVC, AV1, VP9.

Converting the container does not touch the codec, in the same way that moving a document into a different folder does not change the language it is written in. When Windows cannot play your iPhone video, it is essentially always the codec it cannot read, not the .mov wrapper around it.

Why it is HEVC

Since iOS 11, iPhones record in HEVC — also called H.265 — by default, because it produces roughly half the file size of H.264 at the same quality. That is the right trade for a phone with limited storage. It becomes an awkward one the moment the file leaves the phone.

HEVC is patent-encumbered, which is why support for it is uneven. Windows does not ship an HEVC decoder with the operating system; Microsoft moved it into a paid Store add-on. Firefox ships no HEVC decoder on any platform. Plenty of editing software, older TVs and web upload forms are in the same position. Apple devices play it perfectly, which is exactly why the problem stays invisible until you send the file to somebody else.

Why converting MOV to MP4 does not fix it

This is the part most converter sites will not tell you, because their business is to report a successful conversion. Converting a .mov to an .mp4 changes the container. If the video inside was HEVC, the result is an .mp4 containing HEVC — and a machine with no HEVC decoder cannot play that either.

You end up with a new file, a conversion that looked like it worked, and precisely the same black screen. Our own MOV to MP4 tool copies the video stream across untouched and tells you when the result is still HEVC, rather than letting you discover it later on somebody else's computer.

How to tell what you actually have

On Windows, right-click the file, choose Properties, then the Details tab, and look at the video codec. On a Mac, open it in QuickTime and press Cmd+I. In VLC, use Tools then Codec Information. If you see HEVC, H.265 or hvc1, that is your answer.

If it reports H.264 or avc1 and the file still will not play, then the codec is not the problem and the container might genuinely be — that is the rarer case where converting MOV to MP4 is the right fix.

What actually fixes it

Three things work, in rough order of what they cost you.

Install an HEVC decoder on the Windows machine. Microsoft sells 'HEVC Video Extensions' in the Store for a small fee, and some PC manufacturers pre-install it. This fixes every HEVC file at once, alters no files and loses no quality — the right answer when the videos are for you.

Re-encode the video to H.264. This decodes every frame and compresses it again in a format everything can read. It takes real time and costs a little quality, since re-compressing already-compressed video always does, but the result plays anywhere. This is the right answer when you are sending the file to someone whose computer you do not control.

Change what the iPhone records in future: Settings, then Camera, then Formats, then 'Most Compatible'. The phone records H.264 from then on — larger files, no compatibility problem. It does nothing for footage you have already shot, so it complements one of the options above rather than replacing it.

Where this site helps, and where it does not

Our MOV to MP4 tool changes the container without re-encoding, so it is near-instant and lossless, and it is honest about an HEVC video staying HEVC. Use it when you need a .mp4 wrapper for software that insists on the extension.

If what you need is a file that plays on a machine with no HEVC decoder, a container conversion is not it, and no browser-based tool will be quick about the alternative, because re-encoding is heavy work. Installing the decoder on the Windows machine is genuinely the better answer in most cases, and we would rather say so than sell you a conversion that will not help.

Frequently asked questions

Is .mov or .mp4 the problem?

Neither, in almost every case. Both containers can hold the same codecs and Windows supports both. The problem is the HEVC video inside, which is the same before and after a container conversion.

Will converting MOV to MP4 make my iPhone video play on Windows?

Not if the video is HEVC, which iPhone footage is by default. The conversion changes the wrapper and leaves the codec alone, so the result fails on the same machines for the same reason.

Why does the video play fine on my Mac or iPhone?

Apple devices ship with an HEVC decoder, so the file was never a problem there. That is what makes this easy to miss — the file looks perfectly healthy right up until it reaches somebody else.

Is there a free way to play HEVC on Windows?

VLC plays HEVC without any add-on, so it is worth trying before paying for the Store extension. It fixes playback in VLC only — other applications, and Windows' own player, still need the decoder.

Should I just change my iPhone camera setting?

If you regularly share footage with Windows or Android users, yes. Settings, Camera, Formats, 'Most Compatible' makes the phone record H.264. The files are noticeably larger, and it does nothing for the videos already on the phone.