iPhone Videos Won't Play on Windows or Android? Convert MOV to MP4

By Thiago · Updated September 25, 2026 · 3 min read

You send a video from your iPhone and the other person sees a black screen, hears only audio or gets an "unsupported format" error. The problem is almost never the video itself. It's the format it was saved in.

Why MOV files cause trouble

iPhones save videos as .MOV files, Apple's QuickTime format. The file extension is only part of the story. What matters more is the codec inside, the method used to compress the video. Since 2017, iPhones record by default in HEVC (also called H.265) when "High Efficiency" is selected in the camera settings.

HEVC is excellent: it produces files about half the size of the older H.264 at similar quality. But support outside Apple's world is patchy:

• Windows may need a paid extension from the Microsoft Store to play HEVC.
• Older Android phones, smart TVs and car screens often can't decode it.
• Some websites, online course platforms and video editors reject MOV or HEVC uploads.
• The typical symptom is audio with a black screen, or a file that won't open at all.

The fix: MP4 with H.264

The most compatible video format in existence is an MP4 file with H.264 video and AAC audio. Practically every phone, computer, browser, TV and editing app made in the last decade plays it. That's exactly what ConvertKiwi's MOV to MP4 converter produces:

• Video: H.264 at CRF 23, a high-quality setting that looks very close to the original.
• Audio: AAC at 160 kbps.
• Fast start: the file is arranged so it starts playing in a browser before it has fully downloaded, which is important for websites.
• Same resolution and frame rate as your recording.

Step by step

1. Get the video onto your computer, or convert it directly from your phone's browser. On iPhone, the file picker lets you choose from your Photos library.
2. Open MOV to MP4 and add the file (up to 100 MB per file, up to 20 files at a time).
3. Click "Convert to MP4" and wait. Both progress bars show the percentage and the time left.
4. Download the MP4 and send it, or upload it wherever you need.

Will the file get bigger?

Often, yes. HEVC is more efficient than H.264, so the compatible MP4 can be larger than the original MOV, sometimes noticeably. If size matters more than keeping every detail, use the video compressor instead: it also outputs H.264 MP4, but lets you choose a smaller size and resolution. Our guide on reducing video file size explains the levels.

Prevent the problem next time

If you regularly share videos with people on Windows or Android, you can make your iPhone record in the more compatible format from the start:

1. Open Settings → Camera → Formats.
2. Choose Most Compatible.

From then on, new videos are recorded in H.264 (and photos as JPG instead of HEIC). The trade-off: files take roughly twice the storage, and some features like 4K at 60 fps may not be available in this mode on every model. Already have HEIC photos that won't open? Use HEIC to JPG.

Also, when you share a video through apps like WhatsApp, the app converts it for you, at the cost of heavy compression. For full quality, send the converted MP4 as a file or through a cloud link.

Other video formats

The same compatibility problem happens with WEBM (common from screen recorders and browsers), MKV (common for downloads of your own content from some apps) and AVI (older cameras). The MP4 converter accepts all of these and outputs the same universal H.264 MP4.