This plugin for WordPress allows you to add videos to your posts and pages quickly and easily without the need to add custom CSS or learn complex shortcodes. Once posted, the videos resize to the width of the container they reside in no matter how big or small the browser window is.
First, find the YouTube video you want to display on your site. Then click the “Share this video” link. The link should already be highlighted and ready to copy (YouTube makes it pretty fool-proof). Right-click on your mouse and select “Copy”. You can either copy the full URL or just the video ID. The plugin is smart enough figure out which one was entered into the box.
Click on the Responsive Video camera icon.
Paste the YouTube code into the dialog box that pops up. Click OK.
The result is this bit of shortcode. No need to read documentation and learn how to use yet another set of complicated short-codes. Its simple and it works.