How to convert MOV to MP4 on a Mac

MOV and MP4 are both containers, and the video inside an iPhone or screen recording MOV is usually H.264 or HEVC, which MP4 can hold as is. So the fastest conversion often copies the video into a new file without touching a frame. When that won't work, or you want a smaller file, the video has to be encoded again.

Updated October 30, 2026

The short version

With FFmpeg installed, this copies the video and audio into an MP4 without re-encoding, so nothing is lost and it takes seconds:

$ ffmpeg -i input.mov -c copy -movflags +faststart output.mp4

If FFmpeg says it could not find tag for codec, the MOV holds ProRes or another codec MP4 can't carry. Re-encode it instead, as shown in the FFmpeg section.

Pick a method

Rename to .mp4H.264 videos that only need a new nameFree, built in · Apple's guideApple's guide
iMovieOne video, with a quality menuFree from Apple · Apple's guideApple's guide
FFmpegRemuxing without quality lossFree, Terminal · Run on test clipsRun on test clips
convtFolders with subfolders, smaller files$39 once · Run on test clipsRun on test clips

QuickTime Player isn't on the list: its Export As menu saves a new MOV at a different resolution, not an MP4.

Rename an H.264 MOV to MP4

From Apple's guide, Convert a MOV file to MP4 on Mac. We haven't run it ourselves.

Select the MOV in Finder and choose File › Get Info. Under More Info, check that one of the codecs is H.264. If it isn't, use another method.
Control-click the file and choose Duplicate if you want to keep the original.
Control-click the file, choose Rename, change the extension to mp4 and press Return.
Click Use .mp4 when macOS asks.

Apple says the resolution and size stay the same. This works because many players and upload forms read an H.264 MOV fine once it's called MP4. It isn't a real MP4 file underneath, so if a site still rejects it, remux it with FFmpeg or convert it properly.

Export an MP4 from iMovie

From the same Apple guide. We haven't run it ourselves.

In iMovie's Projects view, click Create New and choose Movie.
Click Import, select the MOV and click Import Selected.
Select the clip and choose Edit › Add to Movie (or press E).
Click the Share button and choose Export File. Set Quality to Medium or Low, or lower the resolution, for a smaller file.
Click Next, choose where to save it and click Save.

iMovie is free from Apple and re-encodes the video, so it works for any MOV. It handles one project at a time, which gets slow for a folder of clips.

Convert MOV to MP4 with FFmpeg

Run with FFmpeg 7.0.2 on 8-second 1080p MOV clips in H.264, HEVC and ProRes 422.

FFmpeg is the free command-line tool most video apps are built on. Install it with Homebrew (brew install ffmpeg), then pick one of two commands.

Remux: copy the video into an MP4

$ ffmpeg -i input.mov -c copy -movflags +faststart output.mp4

-c copy copies the video and audio streams as they are, so there's no quality loss and it runs in about the time it takes to copy the file. -movflags +faststart moves the index to the front so the MP4 starts playing in a browser before it has fully downloaded. For HEVC videos from an iPhone, add -tag:v hvc1 so QuickTime and Apple devices recognise the copy.

Re-encode: when remuxing fails

$ ffmpeg -i input.mov -c:v libx264 -crf 23 -preset medium -pix_fmt yuv420p -c:a aac -b:a 160k -movflags +faststart output.mp4

This makes a new H.264 video, which plays almost everywhere. -crf sets the quality: lower numbers look better and make bigger files, and 18 to 28 is the usual range. -pix_fmt yuv420p keeps the video in the 8-bit format every player expects; without it, a ProRes source stays 10-bit 4:2:2, which many players can't play. It takes longer than a remux, because every frame is encoded again.

What came out of our test

H.264 MOV, 14.7 MB: Remuxed in under a second to a 14.7 MB MP4. Same video, new container.
HEVC MOV, 10.8 MB: Remuxed to a 10.8 MB MP4, still HEVC and tagged hvc1.
ProRes 422 MOV, 59.5 MB: Remux failed: MP4 can't hold ProRes. Re-encoding to H.264 made a 5.8 MB MP4.

The ProRes error looked like this, and it means the codec has to change:

FFmpeg error

Could not find tag for codec prores in stream #0, codec not currently supported in container
Could not write header (incorrect codec parameters ?): Invalid argument

To remux every MOV in a folder with FFmpeg, whether it ends in .mov or .MOV, run this in Terminal from that folder:

$ find . -maxdepth 1 -iname "*.mov" -exec sh -c 'ffmpeg -i "$1" -c copy "${1%.*}.mp4"' _ {} \;

It skips subfolders, and it stops with an error on any file that needs re-encoding; that's where convt helps.

Convert whole folders with convt

Run with the released convt 0.5.0 command-line tool on Linux, on MOV files in nested folders. The Mac build bundles FFmpeg and passes it the same arguments.

convt is a Mac and Windows app that converts files on your computer, with a command-line tool in the same install. It brings its own FFmpeg, so you don't need to install it. Local conversions never upload your videos.

Install it with Homebrew, which puts the convt command in Terminal, or from the download page or GitHub releases.

$ brew tap opencoredev/convt https://github.com/opencoredev/convt$ brew install --cask convt

If you installed from the disk image, type /Applications/convt.app/Contents/MacOS/convt instead of convt. To convert a folder and every folder inside it into a separate mp4 folder:

$ convt videos --to mp4 -r -o mp4

Output

videos/2025/trip/b c.mov -> mp4/2025/trip/b c.mp4
videos/2025/x.mov -> mp4/2025/x.mp4
videos/a.MOV -> mp4/a.mp4
3 converted, 0 failed

-r includes subfolders and -o mp4 rebuilds the same folders under mp4. Leave out -o and each MP4 is written next to its MOV. Running the command again writes a (1).mp4 rather than replacing the first copy. convt converts videos one at a time.

convt 0.5.0 always re-encodes: it makes H.264 video (CRF 20, the x264 encoder's medium preset) with AAC audio, whatever the MOV holds. That means ProRes and HEVC files work the same as H.264 ones, but it's slower than a remux, and the copy is a new encode. For a pure remux, use the FFmpeg command above.

Resolution and length: 1920 × 1080 and 8 seconds in, the same out, for all three codecs.
Codec: H.264 High profile and AAC audio in every MP4, including from HEVC and ProRes.
Recording date: Not copied in our test, though a location tag was. FFmpeg's remux kept both.

Or right-click in Finder

From convt's own documentation. We haven't clicked through it in Finder for this guide.

Open convt once, then turn on its Finder extension in System Settings › General › Login Items & Extensions › Finder. After that, Control-click your MOV files, choose Convert with convt, then MP4.

Make the MP4 smaller

Run with the convt 0.5.0 command-line tool on one 8-second 1080p H.264 MOV of 14.7 MB.

A converted MP4 is often smaller than the MOV, but not always. These options trade size for quality, and you can combine them:

$ convt clip.mov --to mp4 --video-height 720 -q 60

--video-height 720: Scales the video down to at most 720 pixels tall. It never scales up.
-q 60: Quality from 1 to 100. The default matches 80.
--video-codec hevc: HEVC instead of H.264: smaller at the same quality, but slower to encode.
--audio-bitrate 96: Audio at 96 kbit/s instead of 192.
--no-audio: Leaves the sound out.

What each option did to our 14.7 MB test clip

No options: 8.6 MB. 1080p H.264 at convt's default quality.
--video-height 720: 2.7 MB. Scaled to 1280 × 720.
-q 40: 2.4 MB. Still 1080p, with more visible compression.
--video-codec hevc: 7.7 MB. HEVC at its default quality.
--video-codec hevc --video-height 720 --audio-bitrate 96: 1.9 MB. All three together.

Our clip was a generated test pattern, which compresses differently from camera footage. Use the numbers to compare options, not to predict your file sizes.

Convert MOV to MP4 on Windows

The commands are the ones we ran on Linux, with Windows paths. We haven't run them on Windows.

The FFmpeg commands above work the same on Windows. With convt installed, its command-line tool sits in your user folder and isn't on your PATH, so give its full path in PowerShell:

$ & "$env:LOCALAPPDATA\Programs\convt\convt.exe" Videos --to mp4 -r -o mp4

Or open convt from the Start menu, drag the MOV files onto its window and choose MP4. convt's right-click menu in File Explorer isn't part of the Windows installer yet.

Questions

Does converting MOV to MP4 lose quality?: Not if you remux: the video is copied, not encoded again. Re-encoding loses a little, and at sensible settings it's hard to see. Converting the same file over and over adds up, so always start from the original.
Is MP4 smaller than MOV?: Not by itself. A remux is the same size, because the video is the same. A re-encode is smaller or bigger depending on the settings: our ProRes clip went from 59.5 MB to 5.8 MB, while an already-compressed H.264 clip barely changed until we lowered the resolution or quality.
Why won't my MOV remux to MP4?: It holds a codec MP4 can't carry, most often ProRes from a camera or a screen recording app. Re-encode it with FFmpeg or convt.
Does convt upload my videos?: Not for local conversions. The app and the command-line tool convert on your computer. The app uploads a file only if you pick Cloud for a job, which is part of convt Pro. See every format it handles on the formats page.