Video
Convert MP4 to MOV on Mac (and MKV to MOV)
To convert MP4 to MOV on a Mac without losing quality, rewrap the file instead of re-encoding it. Run avconvert --preset PresetPassthrough --source in.mp4 --output out.mov in Terminal. It is built into macOS and finishes in about a second for a short clip.
How do I convert MP4 to MOV on a Mac for free?
MP4 and MOV are close relatives. When the video inside is H.264 or H.265 with AAC audio, both containers hold it, so the conversion is just a new wrapper. Apple’s avconvert does this with the passthrough preset:
avconvert --preset PresetPassthrough --source clip.mp4 --output clip.movOn my test clip, the 109,460 byte MP4 became a 107,185 byte MOV, and ffprobe showed the same H.264 video and AAC audio, so nothing was re-encoded. If you prefer ffmpeg, the equivalent is ffmpeg -i clip.mp4 -c copy clip.mov, which gave 109,511 bytes.
In QuickTime Player, File > Export As offers resolution choices and saves a MOV, but it re-encodes. Use it when you also want a smaller resolution, not for a plain container swap.
How do I convert MP4 to MOV with Smol?
- Drag the MP4 files or a whole folder into Smol.
- Choose Convert and set the output to MOV.
- Run it. The MOV is saved beside the original by default, which stays untouched.
Smol re-encodes in a convert. My test file went from 109,460 to 179,354 bytes. That is fine for a few clips, but it is the wrong tool for a pure container swap on a file that is already efficient. The advantage is that one run can handle a folder with mixed MP4, MKV and WebM files at once, and nothing is uploaded.
How do I convert MKV to MOV on a Mac?
Apple’s avconvert cannot read MKV (it failed on my test file), so use ffmpeg for a rewrap:
ffmpeg -i movie.mkv -c copy movie.movThis works when the MKV holds H.264 or H.265 video with AAC audio. My MKV did, and the MOV came out at 110,355 bytes with no re-encode. If the MKV holds a different codec, such as VP9 video or Opus audio, MOV cannot take it as is and you need a re-encode. Smol can do that: drop the MKV in and choose MOV. For the opposite direction see MKV to MP4.
Why would a video not work in Final Cut Pro or iMovie?
Usually the codec, not the container. Final Cut Pro and iMovie import H.264 and H.265 video in MP4 or MOV, but can refuse video from screen recorders and web downloads that use other codecs, and some files with variable frame rate edit poorly. Renaming MP4 to MOV does nothing for those, because the codec stays the same.
Check what is inside with ffprobe -hide_banner clip.mp4. If you see h264 or hevc and aac, a rewrap to MOV is enough. If you see anything else, re-encode to H.264 or H.265 in a MOV. Large camera files can also be cut down first with compressing video on a Mac.
Which method is best for MP4 to MOV?
| Method | Output size (109,460 byte MP4) | Re-encodes | Reads MKV |
|---|---|---|---|
| avconvert passthrough | 107,185 bytes | No | No |
| ffmpeg -c copy | 109,511 bytes | No | Yes |
| QuickTime Export As | Not measured | Yes | No |
| Smol convert to MOV | 179,354 bytes | Yes | Yes, plus AVI |
When is Smol the wrong tool for this?
For a single MP4 to MOV swap, avconvert is free, already installed, and lossless. Use it. ffmpeg covers MKV sources the same way. Smol adds nothing here except a window instead of Terminal.
It pays off when a folder has mixed formats you need in MOV or MP4, when you want a Finder right-click instead of commands, or when a source codec forces a real re-encode and you would rather not hand-write ffmpeg flags. It is $29 once for one Mac: see Smol. More choices are in the best file converters for Mac, and going the other way is MOV to MP4. Shrinking the result is covered in the best video compressor for Mac.
How we checked this
Generated a 5 second 720p H.264 MP4, rewrapped it with avconvert passthrough and ffmpeg, converted it with Smol 1.0.35, and compared sizes and codecs with ffprobe. avconvert also failed on an MKV. Facts last checked . We make Smol, so treat our claims about it with the same care as any vendor’s, and see our editorial policy.
MP4 to MOV: common questions
Is converting MP4 to MOV lossless?
It can be. If the video is H.264 or H.265 with AAC audio, avconvert or ffmpeg can rewrap it into MOV without re-encoding, so quality is unchanged. A tool that re-encodes, such as QuickTime Export As or Smol, rewrites the video and loses a little detail.
Can I just rename an MP4 to MOV?
Sometimes it opens, but it is not a conversion. Renaming changes the extension, not the file structure, so apps that check the real format may complain. Use avconvert or ffmpeg to rewrap properly. The file takes a second to convert and stays lossless.
Is MOV better than MP4?
Neither has better quality, since quality comes from the codec inside. MOV is Apple’s container and the natural choice for Final Cut Pro and iPhone footage. MP4 is the more universal one for sharing, web and Windows. Choose by where the file is going.
Why is my MOV bigger than the MP4?
The conversion re-encoded the video. A rewrap keeps the size about the same: my 109,460 byte MP4 became 107,185 bytes. Smol’s convert re-encodes, and gave 179,354 bytes on the same file. Compress the MOV afterward if size matters.
Does QuickTime convert MP4 to MOV?
Yes. Open the MP4 in QuickTime Player and choose File > Export As, then pick a resolution. It saves a MOV, but it re-encodes the video. For a lossless rewrap with no quality change, use the avconvert command in Terminal.
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