Keep2theCode

IMPORTANT: If you are updating this plugin from an older version, be sure to have backups of any stylesheets or icons, because you will need to re-upload them via the new form.
This plugin allows you to “tweak” or do minor overrides to the style for any theme, much like a child theme. But it also makes it easy to show images for your site’s logo, url, smartphone bookmark, and social sharing at sites such as Facebook.
For styles, first create a style sheet for the theme you want to adjust. For example, if you have a theme called soverycool, you might name your style sheet soverycool.css. Your file only needs to contain those style elements you’d like to change.
Next, upload it via the Upload File form. Once your file is uploaded, just insert its name into the css filename box and press Set Style. If you have several themes, you can keep all of your custom style sheets in that directory as long as they have different names. Then just enter the name for whichever theme you’re using at the time.
To stop using your custom style, just remove the name from the css filename box and press Set Style. You do not need to actually delete your files from the uploads directory.
For icons, upload them via the Upload File form and repeat for each icon. The names have to be favicon.ico, phone.png, share.png, and logo.png. Changing them is as easy as uploading new files with the same name. For your site logo to appear, the following code needs to be added to your theme’s header in the place you want it to appear: <code><?php thtw_logo(); ?></code>

Theme Tweak

Do minor changes to any theme styling, and easily display site images: logo, favicon, smartphone icon, and sharing icon.

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.
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Adoption Notice
</blockquote>
Special thanks to Jon ‘jonradio’ Pearkins for creating the plugin and making adoption possible.

Multiple Themes


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.

Theme Tweak vs Multiple Themes