Video
What is a WebM file?
WebM is a subset of Matroska for web media. It may combine VP8, VP9, or AV1 video with Vorbis or Opus audio; WebM itself is not a single codec or a guarantee of smaller files.
.webmWeb-oriented media container
When to choose this format
- Serving video encoded for a browser and platform known to accept it
When to avoid this format
- Assuming the container alone ensures playback in every editor or device
Common uses
- Web video delivery
Features
- Restricts Matroska to a web-media profile
- May pair VP8, VP9 or AV1 video with supported audio streams
Advantages and disadvantages
Advantages
- Useful as an alternate web delivery source where supported
Disadvantages
- Codec, bitrate and device support vary across workflows
Open and convert
How to open
Open in a compatible browser or player and inspect video and audio codecs if playback fails.
How to convert
MP4 conversion may require re-encoding; verify output quality, audio, and target playback.
Cautions
- Test the exact streams in browsers, CMS and editors; compare quality and size after conversion
FAQ
Is WebM always smaller than MP4?
No. Compare codecs, resolution, bitrate, and encoding settings rather than container names.