This jQuery plugin ensures that you will get the highest quality thumbnails for your HD YouTube videos, regardless of the embedding sizes or the original thumbnail quality settings of the YouTube videos.
Include the CSS stylesheet within the head tag.
<link rel="stylesheet" href="css/YouTube.HD.Thumbnail.css">
Then include the JavaScript file before the closing body tag.
<script src="js/jQuery.YouTube.HD.Thumbnail.js"></script>
Copy the code for embedding from your YouTube video and add a class name like yt-hd-thumbnail.
<iframe class="yt-hd-thumbnail" width="560" height="315" src="https://www.youtube.com/embed/5aOSxep4ni0?rel=0&controls=0&showinfo=0" frameborder="0" allowfullscreen></iframe>
Activate the plugin by adding the following code to your JavaScript file.
$('iframe.yt-hd-thumbnail').youTubeHDThumbnail({ darkenThumbnail: false });
MIT License
Created by Simon Li in Sep 2016