How to identify a WordPress plugin causing issues

Most WordPress problems, from a slow dashboard to a site that won't load, come down to a single plugin (or sometimes a theme). This guide shows you how to find out which one.

Signs a plugin may be the problem

• A slow WordPress dashboard or page editor
• Your website loading slowly
• 503 errors, or your account hitting its resource limits
• A blank page or "There has been a critical error on this website"
• Something stopped working straight after an update

Common reasons a plugin misbehaves:

• It's out of date, or hasn't been updated by its developer in a long time
• It conflicts with another plugin or your theme
• It uses PHP code that's deprecated or removed in your PHP version
• It has a bug, or gets stuck in a loop
• It's been exploited (contact form and custom field plugins are common targets, so keep them updated)

Before you start

Make sure you can restore your site if something goes wrong. We back up your account daily. See Restore files, databases or email from a backup.

Step 1: Check the error log

If you're seeing an error, the log usually names the plugin straight away. Look for a file path like wp-content/plugins/plugin-name/. See Find and read your website error logs.

Step 2: Find slow plugins with Query Monitor

For slowness rather than errors, the free Query Monitor plugin shows what's taking the time.

1. In WordPress, go to Plugins → Add New Plugin, search for Query Monitor, then install and activate it.
2. Visit a slow page or part of the dashboard. Query Monitor adds figures to the admin bar at the top showing load time, memory and database queries.
3. Click those figures to open the panel. Under Queries by Component and Database Queries, look for a plugin that's responsible for lots of slow queries or a big share of the time.
4. Deactivate Query Monitor when you've finished, as it adds a little overhead itself.

Our servers also include X-Ray, which can trace exactly what's slowing a page down. See Using XRAY PHP to diagnose a slow WordPress website.

Step 3: Test without plugins, safely

The free Health Check & Troubleshooting plugin lets you turn plugins off for yourself only, while visitors still see the normal site.

1. Install and activate Health Check & Troubleshooting from Plugins → Add New Plugin.
2. Go to Tools → Site Health → Troubleshooting and click Enable Troubleshooting Mode. All plugins are switched off for you, and a default theme is used.
3. Check whether the problem has gone. If it has, a plugin or your theme is the cause.
4. Use the Troubleshooting Mode menu in the admin bar to turn plugins back on one at a time, checking after each one. When the problem comes back, you've found the culprit.
5. Click Disable Troubleshooting Mode when you've finished.

Alternatively, on a quiet site, you can deactivate plugins one at a time under Plugins and check after each one. This affects visitors too, so do it at a quiet time.

Can't get into the dashboard?

Switch plugins off from cPanel instead:

1. In cPanel, open File Manager and go to wp-content/plugins in your site's folder.
2. Rename the suspect plugin's folder, for example from plugin-name to plugin-name-off. WordPress deactivates it automatically.
3. If you're not sure which plugin it is, rename the whole plugins folder to plugins-off, log in, then rename it back and reactivate plugins one at a time.

Once you've found it

• Update it, along with WordPress and your theme. That fixes most problems.
• Check the plugin's support forum or changelog for known issues.
• If it's no longer maintained, replace it with an alternative that's actively updated.
• If you need the plugin and it's using a lot of memory, raise your memory limits (see below).

Memory limits

If your site is hitting its memory limit, add this to wp-config.php, just above the "That's all, stop editing" line:

define( 'WP_MEMORY_LIMIT', '512M' );

Your cPanel account allows up to 1 GB, so larger sites can use up to 1024M. Make sure PHP's memory_limit in cPanel's MultiPHP INI Editor is the same or higher than the value in wp-config.php. See How to fix "Allowed memory size exhausted" in WordPress and Change your PHP version and settings.

Raising the limit gives a heavy plugin room to work, but if a plugin keeps running out of memory even at 1024M, it's usually faulty and needs updating or replacing. See What are resource limits?

Need help?

If you can't track down the cause, open a support ticket. Let us know which pages are slow or broken and roughly when it started, and we'll take a look.