MOV to MP4 converter
Turn a MOV video (from a phone or a Mac) into an MP4 that plays almost everywhere. Where the codecs already fit MP4, the picture and sound are copied as they are.
How it works
The video is read by ffmpeg.wasm, a full video engine that runs in your browser.
First the streams are copied into an MP4 container, which takes seconds and loses nothing. If the codecs do not fit MP4, the video is re-encoded with H.264 and AAC.
Your files never leave this device. The video engine is downloaded once from jsDelivr the first time you convert a video, then the browser keeps it.
Your files stay on this device. Nothing is uploaded, and the converter runs entirely in your browser.
Questions
Is there a loss of quality?
Not when the streams are copied. Re-encoding happens only when the codecs cannot go into MP4 as they are, and then the quality setting decides the size and sharpness.
Why is the conversion slow sometimes?
Copying is quick. Re-encoding a long or large video takes a while, because the whole job runs on your device.
What is the largest file?
400 MB. Larger files are refused before any work starts, because the browser has to hold the whole file in memory.