video/*
video/mp4
File extensions: .mp4, .m4v
MPEG-4 container — the universal video format on the web.
What is video/mp4?
video/mp4 is the media type for MP4 video — an MPEG-4 container typically holding H.264 or H.265 video and AAC audio. It is the safest bet for cross-browser playback via HTML <video>.
Typical usage
Product videos, tutorials, HTML5 <video>, video ads.
Common gotchas
Older H.264 baseline profile plays everywhere; H.265 (HEVC) has patent/royalty issues and is not supported by all browsers. Provide multiple sources when in doubt.
HTTP header example
Response header
Content-Type: video/mp4Reference
RFC 4337