What is a MP4 file?
MP4 is a widely supported container for video and audio. Compatibility and file size depend on the codecs and settings used inside it, which is why MP4 with H.264 video and AAC audio is a common choice for sharing and uploading.
How to open a MP4 file
MP4 is widely supported by browsers, phones, smart TVs and desktop players. Playback still depends on the video and audio codecs stored inside the file.