HTML video tag - change source on viewport without media attribute

I'm trying to implement a video in HTML with react. So if the viewport is under 750px width, I would like to change the video source to a smaller resolution/ smaller file (because of high data transfer and so on).

Download Instagram videos and photos using HTML, CSS and JavaScript

How can we download Instagram videos and photos using the HTML CSS JavaScript program? Solution: See this JavaScript Instagram Media Downloader. In other words, Program For Save Instagram Photos & Videos

Understanding of Meter Tag in HTML 5

This post explains the HTML 5 meter tag and how to create it