Debugging in WordPress is the process of identifying, diagnosing, and fixing problems on a WordPress website. When something goes wrong—such as a plugin conflict, a broken layout, or the white screen of death—debugging helps you identify the cause.
WordPress includes built-in features for logging and displaying errors, but they are limited. For a more complete and user-friendly debugging process, it’s often helpful to use a debugging plugin.
Why Debugging Is Important in WordPress
WordPress sites rely on the WordPress core, plugins, themes, and the hosting environment working together. If any of these components contain errors or conflicts, they can cause issues such as:
- Pages not loading correctly
- PHP warnings or fatal errors
- Features not working as expected
- Plugin or theme conflicts
- Performance problems
Debugging helps isolate the source of the problem so you can fix it.
How Debugging Works in WordPress
WordPress debugging features are controlled by several constants in the wp-config.php file.
The most important of these constants is WP_DEBUG, which enables or disables WordPress debugging. Developers often combine WP_DEBUG with two other constants:
WP_DEBUG_LOG– Saves errors to adebug.logfileWP_DEBUG_DISPLAY– Controls whether errors appear on the screen
These settings make it easier to track down issues by providing detailed information about what went wrong and where it occurred.
Common Situations Where Debugging Is Used
Debugging is used when a WordPress site starts behaving unexpectedly. Common scenarios include:
- A plugin causes errors after being activated
- A theme update breaks part of the site
- A page displays a blank screen or PHP error
- A custom code snippet stops working
- WordPress shows warnings after an update
By enabling debugging and reviewing the resulting error messages, you can often identify the source of the problem.
When to Use WordPress Debugging
Debugging should typically be enabled only when troubleshooting issues on a development site or temporarily on a live site while investigating a problem. Because debugging messages can reveal technical details, they should not be displayed to visitors on a production website.
Once the issue is resolved, debugging should be disabled again.
WordPress Debugging Tools
In addition to WordPress’s built-in debugging constants and error output, developers may use other tools to diagnose problems, including:
- Hosting server error logs
- Browser developer tools
- WordPress debugging plugins
One debugging plugin that can greatly simplify this process is WP Debug Toolkit.
Debugging WordPress with WP Debug Toolkit
WP Debug Toolkit is designed to support the debugging workflow directly from the WordPress Admin dashboard.
With this plugin, you can:
- Enable the necessary WordPress debugging constants without manually editing the
wp-config.phpfile - View PHP errors and warnings from plugins, themes, and WordPress core
- Search and filter error messages to identify problems faster
- Analyze database queries to identify slow-running queries, repeated or duplicate query patterns, potential N+1 query loops, and the source of those queries
Unlike most WordPress debugging plugins, WP Debug Toolkit is an independent app that runs separately from the WordPress core. Even if a problem crashes your site, the viewer app still works. It also includes a crash recovery system that helps you identify and disable the plugin or theme responsible for the crash so you can log back in to WordPress Admin.
Final Thoughts
Debugging is an essential part of maintaining and troubleshooting a WordPress site. When something stops working as expected, debugging tools help you identify the cause so you can fix the problem.
WordPress includes several built-in debugging features that log and display errors. By enabling these features and reviewing the resulting messages, you can often pinpoint the source of a problem.
If you want to take WordPress debugging a step further, we recommend WP Debug Toolkit.
For a complete list of debugging plugins, see the 7 Best WordPress Debug Plugins.
