neurotraveleu

This plugin adds an “Open In Social Debugger” link to the admin bar. The link opens the current page or post in Facebook Sharing Debugger.
This plugin works with pages and posts, and in both backend and frontend, as long as the admin bar is visible AND the page/post is in a published state.
<h3>Usage</h3>
On any page or post, in frontend or backend, you’ll see a “Open in Social Debugger” link in the admin bar, which opens the Facebook Sharing Debugger with the permalink of the current page/post for debugging.

Open in Social Debugger

This plugin adds an “Open In Social Debugger” link to the admin bar, which opens the current page or post in a social network debugger.

Forge12 Interactive GmbH

This plugin will track the load time of each plugin, javascript and css file 
to help you optimizing the performance of your WordPress site. It will help you 
to figure out which plugin / resource causing the slowness of your page.
Track time for:
<ol>
<li>Core</li>
<li>Theme </li>
<li>Plugins</li>
<li>Resources (JavaScript, CSS)</li>
<li>External files</li>
</ol>

F12-Profiler

Excellent! After P3 doesn’t work with PHP7+ anymore, F12 seems finally the one stepping in to fill that gap.

Update [18-Jun-19]. After some small contributions of mine to the dev efforts, the plugin developer has decided to add me to the team, long after this review was written.

Finally an alternative to P3

Trace the execution time of plugins, themes and core files to find the bottlenecks of your system.

Open in Social Debugger vs F12-Profiler