How to convert MOV to MP4
- Drop your .mov file on the box above (up to 2 GB).
- The tool reads it and shows its size, resolution, length and whether it has sound.
- Click Convert to MP4. For typical files it finishes in about a second and tells you the video was copied without re-encoding.
- Download the MP4. It has the same name as your MOV, with the new extension.
MOV and MP4 are wrappers, not formats of video
A MOV or MP4 file is a container: it holds a video stream, usually an audio stream, and some information about how to play them. The actual picture is encoded with a codec — H.264 or HEVC (H.265) for almost everything a Mac or iPhone records. MOV is Apple’s QuickTime container; MP4 is the international standard that grew out of it, and it can hold exactly the same H.264 and HEVC streams.
That is why this conversion doesn’t need to touch the video. The tool reads the encoded frames out of the MOV and writes them, unchanged, into an MP4 — a process usually called remuxing. No decoding, no re-encoding, no quality change, and the speed is limited only by how fast the file can be read. Converters that re-encode every MOV are doing a lot of unnecessary work and throwing away quality on the way.
Measured
| MOV | Inside | Chrome | WebKit (Safari engine) |
|---|---|---|---|
| macOS screen recording, 148 s, 73.2 MB | H.264, no audio | 0.5 s · 71.7 MB | 1.0 s · 71.7 MB |
| iPhone video, 13 s, 13.6 MB | HEVC + AAC | 0.3 s · 13.5 MB | 0.4 s · 13.5 MB |
The MP4s kept the same codec, resolution and length as the originals, checked with ffprobe; the slight size drop is container overhead. The iPhone clip kept its sound in both browsers, because copying audio needs no encoder.
Why convert at all
- Upload forms, CMSs and learning platforms that accept “MP4 only”.
- Sending a Mac recording to someone on Windows or Android, where MOV preview can be hit or miss.
- Web pages: an MP4 in a video tag is the most widely supported choice.
- Editing and AI tools that list MP4 as their input format.
If the file also needs to be smaller, convert here first and then use the Video Compressor — on real macOS screen recordings it cut size by 87–95%. An iPhone HEVC clip that has to play on older devices should go through the compressor too, since it re-encodes to the more widely supported H.264.
Other ways to convert on a Mac
Finder can re-save a video: right-click it and choose Encode Selected Video Files…. It re-encodes to one of a few presets and writes an .m4v file, which is fine for sharing but slower than a container swap and not lossless. QuickTime Player’s File › Export As works the same way — it encodes a new file at the resolution you pick.
If you are comfortable in Terminal, ffmpeg does the same lossless remux as this tool with one command. It finished our 148-second screen recording with the codec and length unchanged:
ffmpeg -i recording.mov -c copy recording.mp4The -c copy part is what makes it lossless: it copies the streams instead of encoding them. Leave it out and ffmpeg re-encodes everything, which takes far longer and changes the picture.
When the tool has to re-encode
A few MOVs hold video an MP4 can’t carry as-is — older QuickTime codecs, for example. The tool tries the lossless copy first; if that isn’t possible it re-encodes to H.264 at high quality and says so under the result, so you always know which happened. Apple ProRes files from editing apps can’t be decoded by any browser; export an H.264 copy from the editor instead.
