Pardon my pedantry but MP4 is just the container and does not spare you from finding a compatible set of codecs to put in that container that will play on your

Pardon my pedantry but MP4 is just the container and does not spare you from finding a compatible set of codecs to put in that container that will play on your target browser-plus-OS combo. See the video and audio codec table here for example: https://developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats/Containers#mpeg-4_mp4 https://developer.mozilla.org/en-US/docs/Web/Media/Guides/Fo...