The best way to test new WordPress themes

  1. Download the Theme Tester plugin for WordPress, install and activate it.
  2. Download themes from (or maybe not, see Adam’s comment below!) and try them out without annoying your visitors by changing themes on them.

My new Theme Tester plugin allows you to change themes and view the results without the visitors to your blog seeing any changes.
There is one cavaet. Your visitors may notice some changes if your current theme uses blog options that a new theme overwrites. This could happen if for example you’re testing a newer version of your current theme or testing a theme based on the same engine as your current theme. The K2 theme springs to mind here because it’s the base for several other themes but YMMV.

I used the plugin already when I trawled the themes sites and the archives at Weblog Tools Collection for a new theme for this place. As you can guess if you’re a regular visitor, I haven’t changed theme yet, but I found a couple of very pretty designs that may make an appearance here eventually.