Convert WebM to MP4
Settings
No file yet
Settings appear after you choose a file.
Screen recorders and saved web clips come as WebM, while many editors and phone apps ask for MP4. The converted file holds the same clip as an MP4.
WebM or MP4?
Keep WebM when
- It is the original. Encoding it again loses a little detail.
Pick MP4 when
- A program, a site or a device asks for MP4 files.
About WebM and MP4
WebM
An open video format made for the web. Common for screen recordings and clips saved from sites, less so in media players.
MP4
The most widely used video format. It plays on most phones, computers and platforms, and is the usual way video is shared.
Questions
Does the MP4 look worse?
A little. H.264 and AAC are lossy, so encoding the video again drops some detail. A lower CRF loses less.
Is there a copy line?
No. A copy keeps the codecs the WebM already has, and VP8 video with Vorbis sound does not fit an MP4 at all. The lines make the H.264 video and AAC sound that MP4 files usually hold.
Which CRF should I pick?
The commands use CRF 23, a common middle ground between size and quality. Change -crf 23 to a lower number for a better picture and a larger file, or a higher one for a smaller file, 0 to 51.
Can I convert a whole folder at once?
Yes. Drop them all here. In Terminal, one line converts every WebM in the folder.