Mp4 file extension is an MPEG-4 video file format. MP4s are one of the more common video file formats used for downloading and streaming videos from the internet. It's a highly versatile and compressed video format that also can store audio, subtitles, and still images.

MP4 files were created under the ISO/IEC 14496-12:2001 standard by the ISO/IEC and Motion Picture Experts Group (MPEG). Because of this, MP4 is an international standard for audio-visual coding.

Initially created in 2001, MPEG-4 Part 12 was based on the QuickTime File Format (.MOV). The current version—MPEG-4 Part 14—was released in 2003. MP4 is considered a digital multimedia container format—essentially a file containing a bunch of data that’s been compressed, The standard specifies how the data is stored within the container itself, but not how that data is encoded.

Because MP4 is a standardized file format for video, almost all video players support MP4. To open a file, all you have to do is double-click your video, and it will open with your operating system’s default video viewer. Android and iPhone natively support playback of MP4 as well—just tap the file, and you’ll be watching your video in no time.