Babar

Take a snapshot of a website and embed it on your blog post on the fly. No need any screen capture tools, no need any coding. 
Just insert the shortcode, and snapshot will be embed automatically on your post.
Here is an example: <code>[snap url=http://example.com alt="This snapshot has taken by Snap A Site"]</code>
For more details reffer to the User Manual part of the readme.txt file or find <a href="http://en.ibabar.com/snap-a-site#manual" title="Find the user manual of Snap A Site on my blog" rel="follow nofollow ugc">Snap A Site user manual</a>
Still searcing for something? Just drop a message @ <a href="http://en.ibabar.com" title="Use the contact form on my blog" rel="follow nofollow ugc">My Blog</a>
<h3>User Manual</h3>
It’s easy. Just insert this shortcode in your post: [snap url=http://example.com]
Supported parameters for [snap]
<ul>
<li>url – URL of the site to take snapshot</li>
<li>alt – For image alt</li>
<li>h – For imahe height</li>
<li>w – For image width</li>
<li>alt – For image alt</li>
<li>h – For imahe height</li>
<li>w – For image width</li>
<li>title -For link title</li>
<li>target – For link target</li>
<li>rel – For link rel</li>
<li>link – For linking to other site</li>
</ul>
Have further question? Let me know. Just drop a message @ <a href="http://en.ibabar.com" title="Use the contact form on my blog" rel="follow nofollow ugc">My Blog</a>

Snap A Site

The easiest way to take and embed snapshot of a site on Wordpress blog.

webshrinker

This plugin will allow you to automatically show previews of external websites when a user hovers over a link in your posts. 
It’s designed to work “out-of-the-box” and no changes should be needed on your part to make it work. 
However, if you are familiar with CSS, you can apply “link previews” to links in other places in WordPress site by specifying any CSS selector that you want.
A free or paid <a href="https://www.webshrinker.com" rel="nofollow ugc">Web Shrinker</a> account is required as you will need a service API key.
<iframe class="youtube-player" width="640" height="360" src="https://www.youtube.com/embed/1xGf00XQSH8?version=3&rel=1&showsearch=0&showinfo=1&iv_load_policy=1&fs=1&hl=en-US&autohide=2&wmode=transparent" allowfullscreen="true" style="border:0;" sandbox="allow-scripts allow-same-origin allow-popups allow-presentation"></iframe>

Web Shrinker – Website Link Preview Thumbnails

Enhance your post links by enabling a popup preview thumbnail image of the destination website

Snap A Site vs Web Shrinker – Website Link Preview Thumbnails