MP4 file format

MP-4 Part 14
MPEG-4 Part 14 extends over ISO Base Media File Format (MPEG-4 Part 12).[1]
Filename extension	.mp4, .m4a, .m4p, .m4b, .m4r and .m4v[Note 1]
Internet media type	video/mp4 audio/mp4
Type code	mpg4
Magic number	p
Developed by	International Organization for Standardization International Electrotechnical Commission
Initial release	October 2001; 23 years ago (2001-10)
Latest release	ISO/IEC 14496-14:2020 January 2020; 5 years ago (2020-01)
Type of format	Container format
Container for	Audio, video and text
Extended from	QuickTime File Format and MPEG-4 Part 12
Standard	ISO/IEC 14496-14
Open format?	No[2][3]
Free format?	No[2]

MP4 (formally MPEG-4 Part 14), is a digital multimedia container format most commonly used to store video and audio, but it can also be used to store other data such as subtitles and still images. Like most modern container formats, it allows streaming over the Internet. The only filename extension for MPEG-4 Part 14 files as defined by the specification is .mp4.

MPEG-4 Part 14 is a standard specified as a part of the MPEG-4 specifications, formally as ISO/IEC 14496-14:2003. Unlike the audio-only compression formats MP3 and MP2, MP4 is a container format that can hold various types of media from various codecs.^[4] During the 2000s, portable media players were sometimes erroneously advertised as "MP4 players", even if they may play a different format like AMV video and not necessarily the MPEG-4 Part 14 format.