Masahiro NAKASHIMA

The theme can be changed and displayed to only logged in users.
The visitors of the website see your old theme while you are testing the new one.
Only the administrator of the WordPress site sees the new theme that can now be tested safely.
You can also use this plugin instead of “Theme Test Drive” plugin.

WP Theme Test

I have xdebug installed. There are two big Notices.

Threw two big PHP notices

The theme can be changed and displayed to only logged in users.

David Gewirtz

miabou

Settings provide many different ways to Select which Theme should appear where on your WordPress web site:
<ul>
<li>Just for Site Home</li>
<li>By URL (Version 5 adds support for Query keyword=value as part of a unique URL);</li>
<li>By Prefix URL, matching all URLs that begin with the same characters (“Prefix URL”);</li>
<li>By Wildcard Prefix URL with one or more Asterisks (“*”) representing arbritrary subdirectories in the URL;</li>
<li>By Query Keyword found in any URL, not matter what the Value;</li>
<li>By Query keyword=value found in any URL;</li>
<li>By Sticky Query keyword=value that sets the Theme for a given Visitor until an Override Query keyword=value is found in a future URL (Advanced Setting requiring the Visitor’s browser to accept Cookies; incompatible with certain plugins that block Cookies);</li>
<li>Everywhere (Advanced Setting that overrides the WordPress Active Theme);</li>
<li>All Pages (Advanced Setting that works with most, but not all, Themes and Plugins);</li>
<li>All Posts (Advanced Setting that works with most, but not all, Themes and Plugins).</li>
</ul>
None of the Themes in the WordPress Theme Directory alter the appearance of the WordPress Admin panels. As a result, this plugin does not allow Theme Selection entries to specify URLs for WordPress Admin panels.
Use with Paid Themes: On-going full scale testing of Themes by this plugin’s author is only possible if the Theme is found in the WordPress Theme Directory. Although (Version 5 of) this plugin should now work with all Themes, any problems encountered while using Paid Themes will be difficult to diagnose. As described in the FAQ tab, a WordPress Network (Multisite) is an alternative to this plugin, as a way to create a single web site with more than one Theme.
A similar situation exists with Paid Plugins.
Use with Plugins that Cache: You may find that you have to flush the Cache whenever you change Settings in the jonradio Multiple Themes plugin. Some Caching plugins only cache for visitors who are not logged in as users, so be sure to log out before testing the results of your jonradio Multiple Themes settings.
Changing Theme Options (Widgets, Sidebars, Menus, Templates, Background, Header, etc.)?: After installing and activating the plugin, see the plugin’s Settings page and click on the Theme Options tab for important information on changing Options for Themes other than the Active Theme.
How it Works: The plugin does not change the Active Theme defined to WordPress in the Appearances-Themes Admin panel. Instead, it dynamically (and selectively) overrides that setting. Which means that simply deactivating (or deleting) this plugin will restore the way that Themes were displayed prior to installing this plugin. However, in some situations, it is possible to inadvertently alter Theme Options for the Active Theme when using either of the Methods described on the plugin’s Setting page Theme Options tab.
<blockquote>
Adoption Notice
</blockquote>
Special thanks to Jon ‘jonradio’ Pearkins for creating the plugin and making adoption possible.

Multiple Themes

The plugin doesn't seem to work. And the support requires you to register to add a ticket, not useful.

Doesn't seem to work


I didn't expect it to work with wp 6.7.1 and both combination of classic theme and FSE theme. But it works! This was such a pleasant surprise! Excellent idea and realization. I would only suggest that settings interface of a plugin is a little more straightforward. Also, including regex for URL matching would be nice as well.Message to the plugin author - you can update compatibility to match WP 6.7


Fabulous!

Select different Themes for one or more WordPress Pages, Posts or other non-Admin pages.  Or Site Home.

WP Theme Test vs Multiple Themes