Jonathan Desrosiers

Linchpin

Aaron Ware

<blockquote>
Similar functionality has been developed for the <a href="https://developer.wordpress.org/themes/advanced-topics/customizer-api/" title="Theme Customizer API" rel="nofollow ugc">Theme Customizer API</a> and was <a href="https://make.wordpress.org/core/2016/01/28/previewing-site-responsiveness-in-the-customizer/" rel="nofollow ugc">merged into WordPress core as of version 4.5</a>. This plugin will automatically deactivate when you install WordPress 4.5.
</blockquote>
When viewing the front end of the site, a “Responsive” button is added to the WordPress Toolbar. Clicking that will toggle an overlay with your website presented in various sizes for easy responsive design testing.
This can be useful both during theme development, and when writing content to verify it will be presented properly.
This plugin is a heavily modified version of <a href="http://mattkersley.com/" title="Matt Kersley's" rel="nofollow ugc">Matt Kersley’s</a> <a href="http://github.com/mattkersley/Responsive-Design-Testing" title="Responsive Design Testing" rel="nofollow ugc">Responsive Design Testing</a>.

Responsive Page Tester

Gives users with content creating permissions the ability to preview their site in a responsive testbed.

barteled

Have you ever stared at the upgrade button of your favorite plugin with a deep foreboding feeling of what lies ahead? Will this bring your live site to its knees? Or have you wanted to test your new exciting theme without prematurely showing it to the world?
Enter the Sandbox plugin. With two simple clicks an entire testing site is created using your existing hosting provider. No more copying down to a complex local test setup or living dangerously on a live site. A complete independent sandbox, unavailable to the general public and search engines, can be created quickly and simply. You can even create multiple sandboxes to test different iterations of your site.
There is not that much more to say, it’s that easy!
What can I test with this?
Pretty much anything, but here are some examples:
<ul>
<li>Plugin upgrades</li>
<li>Theme changes</li>
<li>Setting changes</li>
<li>Even full, WordPress upgrades</li>
<li>Plugin conflicts? Create a sandbox and disable one at a time.</li>
</ul>
Ok, but how does it work?
When you add a new sandbox, a couple simple parameters are required to differentiate it from other sandboxes. A status is displayed as the sandbox is being created. This can take some time depending on the size of your WordPress install.
Basic steps to creating the sandbox:
<ol>
<li>Copy the tables 
Database tables are copied to new tables with a different prefix and various data within the tables is updated to reflect the sandbox prefix.</li>
<li>Copy the files 
All files are copied to a new folder under the sandbox folder.</li>
<li>Update the configuration 
The configuration file within the sandbox is updated to support the unique sandbox database prefix.</li>
</ol>
Once activated, only your browser can get to the sandbox installation. You can return the live site at anytime by clicking the link in the notice at the top of the admin interface.
Can I use my existing developer tools to edit the sandbox?
Sure. Tools such as Dreamweaver can update the files located in the sandbox directory. A full path is available on the edit screen of the sandbox. Database files can be modified as well. All sandbox tables will have the prefix displayed on the edit screen of the sandbox.
Another beer and coffee fueled creation of <a href="http://think-bowl.com/" title="It's less of a tank and more of a bowl." rel="nofollow ugc">Think Bowl</a>

Sandbox

Create a completely independent test site using existing hosting that is only available to administrators.

Responsive Page Tester vs Sandbox