Convert MOV to MP4
Pick a .mov, get an .mp4. Most files are rewrapped rather than re-encoded, so it takes seconds and loses nothing.
How it works
- Choose the .mov. On an iPhone, pick it from Photos or Files.
- Press Convert to MP4.
- Save the .mp4. On a phone, "Save video" puts it in Photos; on a computer it downloads.
MOV and MP4 are two wrappers around the same kind of video. iPhone, Mac and most camera footage is already H.264 or HEVC inside the .mov, so the converter only rewrites the wrapper. That takes a second or two however long the clip is. If the file holds a codec MP4 cannot carry, such as ProRes, it is re-encoded instead, which takes longer.
Questions
Does it lose quality?
No. The video stream is copied across untouched, so the picture is bit for bit the same as the original.
Why will my MOV not play on Windows or Android?
The wrapper, not the video. Players outside Apple's world handle MP4 far more reliably, even when the video inside is identical.
Why did mine take a while?
The clip needed a real re-encode, usually because it was ProRes or another professional codec. The result is still a standard H.264 MP4.
Does it work on iPhone?
Yes. Open this page in Safari, pick the video from Photos, and use "Save video" when it is done to put the result back into Photos.
Is my video uploaded?
Not unless you choose "On our server". By default everything runs inside your browser and the file never leaves your device. The server option uploads the clip, processes it and deletes it right after the download.
Is there a size limit?
In the browser the clip has to fit in memory, which on a phone means roughly up to a few hundred megabytes. Larger files run fine with "On our server".
The long version, with the built in options on iPhone and Mac: How to convert MOV to MP4, and when a re-encode is needed.