MOV to MP4: How to Make iPhone Videos Play Everywhere

Videos from an iPhone, iPad or Mac often arrive as .MOV files, and some websites, Windows apps and Android phones won’t play or accept them. The fix is usually simple: convert to MP4. Better still, it’s often instant and loses no quality at all. Here’s why, and how to do it with the Video Converter in your browser.

Container vs codec: what’s actually in the file

A video file has two layers:

• The container is the file format: MOV, MP4, WebM or MKV. It’s the box that holds the video and sound and says how they line up.
• The codecs are how the picture and sound inside are compressed: for example H.264 or H.265 (HEVC) for video and AAC for sound.

MOV and MP4 are close relatives, and both can hold H.264 video with AAC sound. When that’s what’s inside, converting MOV to MP4 just moves the same video into a new box. Nothing is re-encoded, so it takes seconds and the quality is identical.

The catch: HEVC

Since the iPhone 7, iPhones can record in HEVC (H.265), which makes files about half the size at the same quality. If Settings → Camera → Formats is set to High Efficiency, that’s what your videos use.

HEVC is excellent, but not everything can play it: some Windows PCs, older Android phones and many websites can’t. For those, an MP4 with H.264 video is the safe choice. Turning HEVC into H.264 means re-encoding the video, which takes longer and makes the file larger, because H.264 needs more data for the same picture.

If you want future videos to be compatible straight away, set Settings → Camera → Formats → Most Compatible: the iPhone then records H.264.

Convert MOV to MP4 in your browser

1. Open the MOV to MP4 converter (or the Video Converter and choose MP4).
2. Drop in your MOV file.
3. Read the line under the file. It tells you whether the video will be copied (instant, lossless) or re-encoded to H.264.
4. Click Convert to MP4, then play the result and download it.

If the video is HEVC and you only need it to play on Apple devices and recent phones, turn on Keep H.265 / VP9 / AV1 video. The tool then copies it into MP4 without re-encoding: faster, and no change in quality, but less compatible.

What about WebM, MKV and the other way round?

• WebM to MP4. WebM videos (common for screen recordings and web downloads) use VP8, VP9 or AV1, which many MP4 players don’t support, so they’re re-encoded to H.264. There’s a ready-made WebM to MP4 page.
• MP4 to WebM. Re-encoded to VP9 with Opus sound. VP9 is efficient, so the file usually gets smaller.
• MKV. It can hold almost any codec, so converting to MKV is nearly always a straight copy.

Why convert on your own device?

Converter websites typically upload your video to their server and send it back, which is slow for large files and means a copy of your video sits somewhere you don’t control. OptiPress reads the file in your browser and does the work with the browser’s own video tools, so nothing is uploaded. For a straight MOV to MP4 copy it usually finishes in a second or two.

Related tools

• Video Compressor: make the MP4 small enough to send.
• Video to MP3: keep only the sound.
• HEIC to JPG: the same compatibility problem, for iPhone photos.