Ryan Duff

Allow admin users to switch which theme they use on your WordPress, WordPress MU, or BuddyPress site. Adds a drop down on the Admin Bar with a drop down to choose from installed themes.

Admin Bar Theme Switcher

Allow admin users to switch which theme they use on your WordPress, WordPress MU, or BuddyPress site.  Adds a drop down on the Admin Bar with a drop d …

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.

Admin Bar Theme Switcher vs WP Theme Test