webm
What is a .webm file?
video/webm
WebM is an open, royalty-free multimedia container based on Matroska, designed for the web and typically carrying VP8 or VP9 video with Vorbis or Opus audio. It is natively supported by modern browsers via HTML5 video. It targets efficient, license-free web streaming.
How to use a .webm file
Use an example WebM to test HTML5 <video> playback, Matroska-based demuxing, VP8/VP9 decoding, and converters between WebM and MP4.