Free · no signup · never uploaded
MOV to MP4 Converter
Turn an iPhone or QuickTime .mov into a universally playable MP4.
Drop a MOV here or choose a file
or drop your file here.
MOV · converted in your browser, never uploaded
Runs in your browser — your file is never uploaded.
Short answer
To convert MOV to MP4, drop your file below and download the MP4. Both formats normally hold the same H.264 video, so the tool rewraps rather than re-encodes — it’s fast and lossless, and runs entirely in your browser.
Guides
MOV and MP4 are more alike than they look
MP4 was actually derived from Apple’s QuickTime (.mov) format, and both are containers built on the same underlying structure. In practice an iPhone .mov and an MP4 usually hold the identical H.264 video and AAC audio inside — the difference is mostly the wrapper and the file extension. That’s why converting between them is a rewrap rather than a real conversion, and why it finishes in seconds with no quality loss.
Why bother converting at all?
Compatibility. MP4 is accepted essentially everywhere — Android, Windows, web players, editors, and upload forms — while .mov is still occasionally rejected or refuses to preview outside the Apple ecosystem. If something won’t accept your iPhone video, rewrapping it as MP4 usually fixes it outright, without touching quality.
Video formats to MP4 — what happens to your file
| Input format | Usual codecs inside | Conversion | Max file size |
|---|---|---|---|
| MOV (QuickTime) | H.264 + AAC | Rewrap (lossless) | 500 MB |
| MKV (Matroska) | H.264 + AAC | Rewrap (lossless) | 500 MB |
| WebM | VP8/VP9 + Opus | Re-encode to H.264 | 100 MB |
| AVI | MPEG-4/DivX | Re-encode to H.264 | 100 MB |
| GIF | Animated GIF | Re-encode to H.264 | 200 MB |
A rewrap copies the existing video and audio streams into an MP4 container untouched — it is lossless and finishes in seconds. A re-encode decodes and re-compresses, so it takes longer and loses a little quality. Size caps differ because everything runs on one thread in your browser.
How this conversion works
Everything happens locally in your browser with ffmpeg — here is exactly how:
- Load the engine. ffmpeg compiled to WebAssembly loads once from this site — your file is never uploaded.
- Copy the streams. the existing video and audio are copied verbatim (-c copy) out of the QuickTime container and into an MP4 one.
- Optimise for playback. the moov atom is written to the front (+faststart) so the MP4 starts playing before it has fully downloaded.
Assumptions
- Everything runs client-side; the streams are copied, never re-encoded.
- Quality is identical to the source.
- Codecs that MP4 can’t hold (such as ProRes) can’t be rewrapped and will report an error.
Last reviewed: July 19, 2026
Frequently asked questions
How do I convert a MOV to MP4?+
Drop your .mov in above and press convert. Because both formats normally carry the same H.264 video, it rewraps rather than re-encodes and finishes in seconds — all in your browser.
Are my videos uploaded to a server?+
No. Everything runs 100% in your browser using ffmpeg compiled to WebAssembly, so your file never leaves your device. Nothing is uploaded, stored, or sent anywhere — and once the converter has loaded it even works offline.
Does this lose any quality?+
No. The existing video and audio streams are copied into the MP4 container untouched, so the result is bit-for-bit the same quality as your original.
Why is it so much faster than other converters?+
Because nothing is decoded or re-encoded. Most online converters re-encode everything by default, which is slow and lossy; rewrapping just changes the container.
Why is the first conversion slower?+
The first time, your browser downloads the ffmpeg engine (about 31 MB) and starts it up. That happens once — later conversions reuse the loaded engine and are much faster.
What if my MOV uses ProRes?+
A ProRes .mov can’t simply be rewrapped into MP4, so that file will report an error. Those need a true re-encode — compress it with the video compressor instead.
Related tools
Video is processed entirely in your browser with ffmpeg and never uploaded.