It’s a rare and wonderful feeling when I come across a development tool that gives me that, “Where have you been all my life?” feeling. Firebug was one. GoDaddy’s P3 (Plugin Performance Profiler) is another.
I formally used a variety of web-site performance testing sites in order to measure the loading speed of sites I developed, but often pinpointing problem WordPress plugins meant testing with the plugin deactivated, re-testing with the plugin activated, going one-by-one through a site’s plugins, or poring through the server logs to find the resource hogs. It wasn’t fun, and it was very time-consuming.
The P3 (Plugin Performance Plugin) makes finding out which WordPress plugins are performing well–and which are not–much easier.
Using the plugin is very easy. It’s installed via the WordPress admin plugin installer like any plugin, and leaves a “P3 Plugin Profiler” entry in the Tools menu in WordPress. Go there, and click Auto Scan. You’ll be presented with a variety of graphical representations of the loading time for each of your installed plugins, including the P3 Plugin Profiler, and can quickly determine which are causing problems.
My favorite view is the “Detailed Breakdown,” but there is a lot of good information on the other tabs, as well.
I’ve found it’s sometimes necessary to run a given test several times and average the results in order to get the most accurate overall loading speed for a site, but the proportionate results for a given plugin are remarkably stable between test runs.
I recommend it to anyone developing for WordPress.