Chris Baldelomar

This plugin was designed and tested to work with <a href="http://angiemakes.com/feminine-wordpress-blog-themes-women/" rel="nofollow ugc">Angie Makes WordPress themes</a>.
This plugin will automatically resize your videos inserted in your WordPress editor. The code is light and only uses CSS. No javascript is used so there is no delay in your iframes and/or embeded objects from being resized. This plugin will also try to correctly guess your aspect ratio so your videos always look great. And if the aspect ratio is not correctly identified, then you can easily apply the correct aspect ratio using CSS. Every video is assigned a unique class name.
It currently has been tested for the following providers:
<ul>
<li>YouTube</li>
<li>Vimeo</li>
<li>DailyMotion</li>
<li>WordPress TV</li>
<li>Embed</li>
<li>Object</li>
<li>Iframe</li>
</ul>
<a href="http://hallie.angiemakes.com/blog/" rel="nofollow ugc">Live Demo & Documentation</a>

Responsive Videos by Angie Makes

Works great! Don't need to set up things, just activate the plugin and enter the videos on posts and pages. Thanks a lot!

Works great!

Simple responsive video plugin. Automatically determine aspect ratio. CSS only. No Javascript.

INN Labs

Pym.js Embeds provides shortcode and Gutenberg block wrappers for embedding responsive iframes using <a href="http://blog.apps.npr.org/pym.js/" rel="nofollow ugc">Pym.js</a>, developed by the NPR Visuals Team. Embedded content resizes vertically to match its container’s width.
AMP compatibility is provided by the <a href="https://wordpress.org/plugins/amp/" rel="ugc">official AMP plugin</a>.
<h3>Pym.js Resources from NPR</h3>
You may also want to look at NPR’s Pym.js resources:
<ul>
<li><a href="http://blog.apps.npr.org/pym.js/" rel="nofollow ugc">Pym.js homepage</a></li>
<li><a href="https://github.com/nprapps/pym.js/" rel="nofollow ugc">Pym.js repo on GutHub/nprapps</a></li>
</ul>

Pym.js Embeds

A WordPress block and shortcode for embedding iframes that are responsive horizontally and vertically, using the NPR Visuals Team's Pym.js.

Responsive Videos by Angie Makes vs Pym.js Embeds