How to convert MOV to MP4
- Choose the MOV files from your computer or phone.
- Keep Format on MP4 and Video codec on Automatic (copy when possible).
- Select Convert to MP4.
- Download the MP4 files, or all of them as a ZIP.
Worked example
In the converter's automated test, a 2-second 320×180 file named clip.mov with H.264 video and AAC sound becomes clip.mp4 with both tracks copied, not re-encoded; ffprobe reads 48 frames of H.264 at 320×180 with AAC audio.
Formats and limits
| Input | MOV |
|---|---|
| Output | MP4 |
| Limits | Input files up to 4 GB are read in pieces; the converted file is built in memory, so outputs above about 2 GB may fail. Needs a browser with WebCodecs (current Chrome, Edge, Safari 17+ or Firefox 130+). Other browsers are told so before any work starts. |
| Engine | Mediabunny (WebCodecs): streams are copied when compatible, otherwise re-encoded; MP3 via a WebAssembly encoder |
Limitations
- HEVC stays HEVC unless you choose H.264 under Video codec.
- Video in a codec the browser cannot decode cannot be converted.
- Only the main video and audio tracks are kept.
- Needs a browser with WebCodecs: current Chrome or Edge, Safari 17 or later, or Firefox 130 or later. Other browsers are told so before any work starts.
Questions
Does MOV to MP4 reduce quality?
Not for H.264 or HEVC video with AAC sound: both are copied unchanged, and the file list says copied, not re-encoded. Other codecs are re-encoded where the browser can decode them.
My MP4 does not play on an older device. What can I do?
iPhone videos are often HEVC, which is copied as HEVC. Choose H.264 (AVC) under Video codec to re-encode the video into the codec almost every player supports.
Are my iPhone videos uploaded?
No. The MOV is read in pieces and the MP4 is built in your browser; nothing is sent to a server.
Privacy
Runs on your device. Files and text are processed in this browser tab and are not uploaded.
This page opens the Video format converter ready for this task. See the privacy policy for how toolsdocks handles data.