I was working on a new site build for a client, when they asked me if I could see why the WordPress dashboard was loading so slowly. The site was still in development, so I had been installing plugins to meet the functionality requirements for the project. It was a custom WooCommerce build, so I had quite a few extensions and custom plugins running on the site.
My first step to diagnose the problem was installing P3 Plugin Performance Profiler. After installation I ran a scan on the site. This is always my first action when I think a plugin could be the culprit of a slow loading site. In this case, however, the results of scan didn’t reveal a blatantly obvious solution to the problem.
My next plugin I installed was Query Monitor. This plugin adds a section to the admin toolbar with tons of diagnostic information about every page load. I checked the scripts tab to see if too many scripts were being loaded. I checked the notices log to see if any errors were causing things to break. Nothing so far.
When I clicked on the HTTP Requests tab, I found the problem. One of the plugins was making authentication requests to a third party service. Since the site was password protected (it was in development), those two requests were timing out on every page load. By deactivating the plugin for now, the site instantly ran lightening fast again.
These plugins won’t always work to solve a slow loading site mystery, but they are a good place to start. Troubleshooting is an art form, and this is just one of the methods I use when working with WordPress.