What you should know
MOV to MP4 is the most common video conversion, because iPhones and QuickTime produce MOV while the rest of the world reads MP4. In the best case, an H.264 MOV becomes MP4 by simply rewriting the container, without touching the image.
If the MOV carries ProRes or a less common codec, conversion requires a full re-encode: the file loses quality but gains compatibility it did not have.
Strengths
- Lossless when the video is already H.264
- Much faster than re-encoding in that same case
- Makes the video readable on Windows, Android and sharing platforms
- Keeps the AAC audio track untouched
Limitations to know
- ProRes and HEVC force a re-encode
- A multi-track MOV may lose unselected tracks
- Conversion does not make a video sharper
- A poorly chosen bitrate can degrade a good-quality video
When to use it
Convert as soon as the video must leave your Apple device: sending to a relative, publishing online, playing on a TV or PC. If you are only archiving it, the original MOV is enough.
Quality, size and compatibility
Remuxing preserves the original quality exactly. Re-encoding depends on the chosen bitrate and setting: start from the original quality, and reduce size only when that is the goal.
Frequently asked questions
- Does MOV to MP4 lose quality?
- Not if the video is H.264: tracks are copied without re-encoding. In ProRes or HEVC a re-encode takes place and slight loss is unavoidable.
- Why is the conversion instant?
- Because no encoding is needed: only the container changes. This is the favourable case, and it covers most iPhone videos.