Make Youtube/Vimeo Videos Fluid and Responsive With The fit-vids Web Component
A lightweight web component for easy responsive Youtube/Vimeo video embeds without jQuery.
JavaScript & CSS responsive video
Lightweight JS Library For Responsive Embedded Content – reframe.js
reframe.js is a lightweight and pure JavaScript library which makes any embedded content (e.g. iframes, videos, Youtube videos) fully responsive to fit any screen size.