Martin Lormes

Automagically adds Open Graph tags to your blog. Control how your posts and pages are presented on Facebook and other social media sites. No configuration needed.
When someone likes or shares your blog on Facebook, your header image is shown. If someone likes or shares a post, the featured image (post thumbnail) is shown. If you haven’t selected a featured image, then the plugin looks for the first image inside the post. If there aren’t any images in your post, then your blog’s header image is shown.
For more information on the Open Graph protocol go to http://ogp.me/

Open Graph Pro

Adds Open Graph tags to your blog. Control how your posts and pages are presented on Facebook and other social media sites. No configuration needed.

Jay Holtslander

<a href="https://wpvulndb.com/plugins/structured-data-test-button" rel="nofollow ugc"></a>
Adds a “Test Data” link in the admin bar (when viewing any page or post) which opens the current URL in <a href="https://search.google.com/structured-data/testing-tool" rel="nofollow ugc">Google’s Structured Data Testing Tool</a>. (You must have the admin bar enabled to see it.)
<h3>Introduction to Structured Data</h3>
Structured data markup describes things on the web, along with their properties. For example, if your site has recipes, you could use markup to describe properties for each recipe, such as the summary, the URL to a photo for the dish, and its overall rating from users.
When you provide structured data markup for your online content, you make that content eligible to appear in two categories of Google Search features:
<ul>
<li>Rich results — Structured data for things like recipes, articles, and videos can appear in Rich Cards, as either a single element or a list of items. Other kinds of structured data can enhance the appearance of your site in Search, such as with <a href="https://developers.google.com/search/docs/data-types/breadcrumbs" rel="nofollow ugc">Breadcrumbs</a>, or a <a href="https://developers.google.com/search/docs/data-types/sitelinks-searchbox" rel="nofollow ugc">Sitelinks Search Box</a>.</li>
<li>Knowledge Graph cards — If you’re the authority for certain content, Google can treat the structured data on your site as factual and import it into the <a href="http://www.google.com/intl/es419/insidesearch/features/search/knowledge.html" rel="nofollow ugc">Knowledge Graph</a>, where it can power prominent answers in Search and across Google properties. Knowledge Graph cards appear for authoritative data about <a href="https://developers.google.com/search/docs/data-types/corporate-contacts" rel="nofollow ugc">organizations</a>, and <a href="https://developers.google.com/search/docs/data-types/events" rel="nofollow ugc">events</a>. <a href="https://developers.google.com/search/docs/data-types/reviews" rel="nofollow ugc">Movie reviews</a>, and <a href="https://developers.google.com/search/docs/data-types/tv-movies" rel="nofollow ugc">movie/music play actions</a>, while based on ranking, can also appear in Knowledge Graph cards once they are reconciled to Knowledge Graph entities.</li>
</ul>
<a href="https://developers.google.com/search/docs/guides/intro-structured-data" rel="nofollow ugc">Learn more</a>

Structured Data Test Button

I made this plugin

Adds a “Test Data” link in the admin bar (when viewing any page or post) which opens the current URL in Google's Structured Data Testing Tool.

Open Graph Pro vs Structured Data Test Button