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find slow plugin

Your site's getting popular, but with the increased traffic, it seems slower. You picked a fast host, enabled caching, but for some reason, it's still loading slowly. What's causing the performance issue?

The answer is that it's likely an unoptimized WordPress plugin. One slow plugin can slow down the entire site.

This tutorial will introduce you to P3 (Plugin Performance Profiler). With it, you'll be able to see each plugin's performance on the site.

Install P3

  • In the admin, go to Plugins > Add New.
  • Search for P3
  • Click "Install Now" and than activate the plugin.
How to Find a Slow WordPress Plugin

Running the First Scan

  • Go to Tools > P3 Plugin Profiler.
  • Click "Start Scan".
  • Enter a scan name (no spaces).
  • Click "Auto Scan".

Pro Tip: If only certain pages are giving you trouble, you can do a Manual Scan and navigate to those pages in P3.

  • You'll see a message, "Scanning is complete".
  • Click "View Results".

Plugin Performance

Along the top, you'll be able to see some overall stats for your plugins. In the tabs below, you'll see breakdowns per plugin.

Runtime by Plugin: This is a pie chart showing a percentage of each plugin's total. If you hover over each part, it will also show the time of each.

Detailed Breakdown: This is bar graph showing the load time of each plugin.

Also, it shows the load time of the WP Core (in blue) and your theme (in red).

The gold line across the top is the total load time of the site. If it's under one second, you're in good shape. If it's over two seconds, and there's one plugin that's taking up most of the load time, that's the slow plugin.

Simple Timeline: A summary of plugin, core, and theme performance for each page.

Hover your mouse over each dot to see which page was tested.

If one or more of the pages takes significantly longer than the others, you can run a manual scan for it to find the offending plugin. Or, use the Detailed Timeline, which we'll show you next.

Detailed Timeline: This shows each page's performance for each plugin, for WP core, and for the theme.

Each dot that's lined up vertically is for a specific page. Hover your mouse over a dot to see the page URL.

Query Timeline: This shows the total number of queries per page.

Generally, the more queries, the slower the page load. If some of your pages are getting thousands of queries, this is likely why they are slow.

Advanced Metrics: This shows averages of key metrics for your site's performance.

You can hover your mouse over each bolded term to get more detailed information.

Resolution

Based on the above data, you should be able to see a plugin that's taking significantly longer than others to load. If it's accounting for 50% or more of your total load time, there's cause for concern.

To resolve the issue, report it to the plugin's developer. The developer will be able to look into it in detail and provide a solution.

If it's not an essential plugin for your site, you can temporarily deactivate it from Plugins > Installed Plugins.

Additional Tips

If you're looking for additional performance tips, check out our Speeding Up WordPress class. Or, share your tips in the comments below.


About the author

Nick is the Director of Support at OSTraining and you can find him in almost every area of the site, from answering support requests and account questions to creating tutorials and software.