How to Enable WordPress Debugging and Safely Read Error Logs

When a WordPress site starts showing a blank page, a fatal error, broken functionality, or an unexpected warning, guessing is rarely the fastest way to find the cause. WordPress has built-in debugging tools that can record useful error information and help you narrow the problem down.

This guide explains how to enable WordPress debugging, find the log, interpret common entries, and turn debugging off when you are finished. The goal is not to leave debugging permanently enabled on a live site, but to use it as a controlled troubleshooting tool.

What Is WordPress Debugging?

WordPress includes a debugging mode controlled by the WP_DEBUG constant. When enabled, WordPress can report PHP errors, warnings, notices, and deprecated-function messages that may help explain why a feature is failing.

The most useful companion setting is WP_DEBUG_LOG, which writes errors to a log file instead of requiring you to catch an error on screen. WP_DEBUG_DISPLAY controls whether those messages are displayed in the page output. WordPress recommends using these tools primarily in development and staging environments. citeturn0search0turn0search3

Before You Enable Debugging

Make a backup before editing wp-config.php.
If possible, reproduce the problem on a staging or development copy.
Record what changed immediately before the problem appeared.
Do not share logs publicly without reviewing them for sensitive information.

How to Enable Debug Logging

Open your site’s wp-config.php file and add or update these constants before the line that says /* That's all, stop editing! Happy blogging. */:

define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );
@ini_set( 'display_errors', 0 );

With this configuration, WordPress records errors in the debug log while keeping them out of the normal page output. WordPress documentation specifically describes WP_DEBUG_LOG as useful for reviewing errors that happen during requests such as Ajax calls or WP-Cron runs. citeturn0search0

Where Is the WordPress Debug Log?

With the standard configuration, the log is usually located at:

wp-content/debug.log

You can access it through your hosting file manager, SFTP, or another server-management method. The exact access method depends on your hosting environment.

How to Read a Debug Log Entry

A typical PHP error contains several useful clues: the severity, message, file path, and line number. For example, an entry may point to a plugin file and identify the function or operation that failed.

Do not assume that the file mentioned in the error is always the root cause. A plugin may trigger a failure because another plugin, theme, PHP version, server setting, or WordPress change exposed an incompatibility.

Look for the First Relevant Error

If the log contains hundreds of lines, start around the time the problem occurred. Look for the first fatal error or warning that appears immediately before the visible failure.

Pay attention to:

Fatal error: PHP could not continue the requested operation.
Warning: PHP encountered a problem but may have continued.
Deprecated: Code is using functionality that may no longer be recommended and could need updating.
Plugin or theme file paths: These can provide a strong clue about which component needs investigation.

Use the Log to Investigate Plugin and Theme Conflicts

If an error consistently points toward one plugin or theme, test the theory rather than immediately deleting anything. On a staging site, deactivate the suspected component and reproduce the problem. If the problem disappears, reactivate components one at a time to confirm the conflict.

This approach works particularly well for fatal PHP errors, editor problems, broken frontend features, and failures that began after installing or updating a plugin.

Debugging WordPress After an Update

If a problem started immediately after a WordPress, plugin, theme, or PHP update, compare the timestamps in the log with the update. Then check whether the affected component has a compatible version available.

A useful troubleshooting sequence is:

Identify exactly what stopped working.
Note when the problem started.
Check the PHP and WordPress logs.
Identify the first relevant error.
Test the suspected plugin or theme on staging.
Apply the smallest appropriate fix.
Retest the original workflow.

Do Not Display Debug Errors to Visitors

Displaying PHP errors on a public website can reveal implementation details that visitors do not need to see. WordPress provides WP_DEBUG_DISPLAY so you can keep errors out of the page while still logging them for investigation. citeturn0search0

Also remember that a debug log can contain paths, database-related information, usernames, or other details that should not be published. WordPress documentation warns that publicly accessible log files can create a security risk. citeturn0search15

How to Turn Debugging Off

After you have finished troubleshooting, restore the normal production settings:

define( 'WP_DEBUG', false );
define( 'WP_DEBUG_LOG', false );
define( 'WP_DEBUG_DISPLAY', false );

If you enabled debugging temporarily, review the wp-content directory and your hosting configuration as well. Do not leave an unnecessarily exposed debug log accessible from the web.

When the Debug Log Does Not Show the Problem

A missing useful entry does not mean there is no problem. Some failures happen before WordPress can write to its own log, while others are caused by the web server, PHP-FPM, database server, firewall, CDN, or hosting environment.

In those cases, check your hosting provider’s PHP and server logs and compare the timing with the WordPress error. If you do not have access to those logs, provide your host with the exact time of the failure and the symptoms you observed.

Final Takeaway

WordPress debugging is most useful when it turns a vague problem into a specific lead. Enable logging in a controlled environment, reproduce the problem, inspect the relevant entries, test the suspected cause, and disable debugging when the investigation is complete.

If the error points to a plugin or theme, you can continue with a controlled conflict test rather than making several changes at once. That makes it much easier to identify the real cause and avoid creating new problems while fixing the original one.

Last reviewed: September 17, 2026.