How to Use WordPress Debug Log (Top Tips & Best Practices)

Do you want to use the WordPress debug log to troubleshoot the issues? This article will show you how to use WordPress debug log properly!

When you run a WordPress website, you might deal with custom codes, different plugins, etc. In some cases, this causes conflicts on your website. That’s when debugging comes to help.

Keep reading this article if you need to know how to debug your WordPress issues perfectly. Here, we will show you how to use a WordPress debug log for good.

First, let’s see what a WordPress debug log is and why it is used.

What Is WordPress Debug Log and Why Use It

The WordPress Debug Log is essential for anyone managing or developing WordPress websites. It’s a log file where WordPress records errors, warnings, and notices that occur as your site operates.

By default, WordPress doesn’t log these errors to keep the site running smoothly, but when debugging is necessary, the debug log becomes invaluable. You’ll find this log file in the wp-content directory, named debug.log, once it’s enabled.

Debugging is critical for identifying and resolving issues on your site. Whether you’re dealing with a plugin that’s not behaving as expected, a theme conflict, or even server-side problems, the debug log provides detailed insights into what’s going wrong.

For developers, it’s a first-hand account of the site’s health, showing where and why errors occur. It’s a diagnostic tool for site administrators that can help pinpoint issues before they become visible to users, ensuring a smoother, more reliable experience.

Now you know what a debuglog is and why it is important. The next section will show you how to use the debug log for troubleshooting.

How to Use WordPress Debug Log for Troubleshooting

We will split it into 7 sections:

• Enable debugging
• Reproduce the issue
• Check the log file
• Analyze log entries
• Fix the errors
• Test your changes
• Disable debugging

Below, we will explain each section.

1. Enable Debugging

The first step in using the WordPress Debug Log for troubleshooting is to enable debugging. This involves modifying your WordPress configuration file, known as wp-config.php, located in your WordPress installation’s root directory. Here’s how to do it:

You’ll need to use an FTP client like FileZilla or access your site’s files via cPanel’s File Manager to open this file. If you’re new to this, ensure you have backup copies of your site before making changes.

In this case, we will use a file manager plugin. What you need to do is find the wp-config.php file and edit it.

If you scroll to the bottom, you will see a line that says the following:

('WP_DEBUG', false);

You need to replace it with the following:

// Enable WP_DEBUG mode
define( 'WP_DEBUG', true );

// Enable Debug logging to the /wp-content/debug.log file
define( 'WP_DEBUG_LOG', true );

// Disable display of errors and warnings
define( 'WP_DEBUG_DISPLAY', false );
@ini_set( 'display_errors', 0 );

Once you have done this, move to the next step.

2. Reproduce the Issue

Once you’ve enabled debugging, reproducing the issue you’re trying to troubleshoot is the next step. This step is critical because it’s the only way to capture the exact errors related to the problem in your debug log.

Clearly define what the issue is. Is it a specific page not loading? A form not submitted? An error message appearing under certain conditions? Understanding the specifics will guide your actions.

Sometimes, reproducing the issue might not work on the first try. You might need to repeat the steps several times, especially if it’s an intermittent issue. Each attempt should be logged, so patience is key here.

3. Check the Log File

Once you’ve successfully reproduced the issue with debugging enabled, the next step is to check the debug log file to see what errors or warnings have been recorded.

Navigate to your WordPress wp-content directory, where you’ll find the debug.log file. This can be done using an FTP client, your hosting’s file manager, or SSH if you’re comfortable with command-line interfaces..

4. Analyze Log Entries

Use a text editor like Notepad++, Sublime Text, or any editor that can handle large files since debug logs can grow significantly. If you’re using SSH, you can use commands like tail -f debug.log to see the latest real-time entries.

Not all log entries will be relevant to your specific issue. Look for entries that coincide with the time you reproduced the problem.

5. Fix the Errors

After identifying the errors in your debug log, the next crucial step is to address and fix these issues. First, understand the error by researching what it means. Common errors might involve syntax issues in your PHP code, conflicts between plugins, or warnings about deprecated functions.

Once you grasp what the error signifies, use the file and line number provided in the log entry to locate the exact source of the problem in your theme, plugin, or custom code files. When dealing with plugin or theme-related issues, start by deactivating all plugins and reactivating them individually.

This process helps you pinpoint which plugin might be causing the error. If the error disappears when a certain plugin is off, that’s your culprit. For theme issues, switch to a default WordPress theme to see if the problem persists; if it doesn’t, the error likely originates from your current theme.

You might find syntax mistakes like missing semicolons or mismatched parentheses for PHP errors. These can be fixed by correcting the syntax in the affected file. If you encounter warnings about deprecated functions, you must update your code to use the newer, recommended functions.

WordPress documentation or PHP manuals are great resources for understanding these changes. Database errors require a look at your SQL queries or database structure. You might need to use a tool like phpMyAdmin to manage and troubleshoot. Ensure your database schema matches the current WordPress standards, which can change with updates.

6. Test Your Changes

After you’ve made corrections based on the errors logged, testing your changes is essential to ensure the problem has been resolved and that no new issues have surfaced. Begin by revisiting the exact conditions or actions that previously triggered the error.

If it was a specific page that wasn’t loading, go back to that page. If it involves a form not being submitted, try submitting it again. This step confirms that the fix works in your site’s real-world scenario.

While testing, pay close attention to the user experience. Ensure that everything functions as expected, not just regarding error messages disappearing but also performance and usability. Sometimes, fixing one issue can inadvertently cause another, like a performance hit or a UI glitch.

Next, check the debug log once more.

Look for any new entries that might have been logged during your test. Even if the original error is gone, there might be other warnings or notices you weren’t aware of before, which could indicate minor issues or areas for improvement. This step helps in catching any side effects of your changes.

7. Disable Debugging

Once you’ve fixed the issues and tested your changes, disabling debugging, especially on a live site, is crucial to prevent performance degradation and potential security risks.

Here’s how to go about it: After troubleshooting, revisit the wp-config.php file where you initially enabled debugging. Open this file using your preferred method, whether through an FTP client, your hosting’s file manager, or SSH using command line tools.

Revert the changes you did in the first step and you are good to go.

That’s it!

This is how you can use the WordPress debug log for troubleshooting.

Expert Tips to Follow

Here are some of the expert tips you might find helpful:

Understand the Difference Between Errors, Warnings, and Notices

Not all log entries are equal. Errors are critical, often stopping the execution of code. Warnings suggest potential issues that might not immediately affect functionality but could lead to problems.

Notices are usually about minor issues like undefined variables or using deprecated functions. Knowing this helps prioritize your debugging efforts, focusing first on errors, then warnings, and addressing notices when time allows.

Leverage WP-CLI for Log Management

If you’re comfortable with command-line interfaces, WP-CLI can be a powerful ally.

Use commands like wp debug log to tail the log file live, wp debug log clear to clear the log after resolving issues, or wp debug log show to view the log contents quickly. This can significantly speed up your debugging process, especially for managing multiple sites.

Combine Debug Log with Browser Developer Tools

While the debug log gives you server-side insights, client-side issues (JavaScript errors, CSS conflicts) are better debugged using browser developer tools.

Use both in tandem. Check your debug log for PHP errors, then switch to browser tools for front-end debugging. This holistic approach ensures you catch issues across all layers of your site.

Monitor Log Size and Use Log Rotation

The debug log can grow significantly, impacting server performance if not managed. Implement log rotation to keep the file size under control.

You can automate this with server-side tools like logrotate or use plugins like “WP Log Viewer” which manages log rotation and provides an interface to view logs directly from the WordPress admin area.

Use a Staging Environment for Debugging

Debugging on a live site can be risky, exposing errors to your users or even causing downtime. Always debug in a staging environment that mirrors your live site.

This way, you can safely test changes without affecting your visitors. Use tools like WP Stagecoach, Duplicator, or manual database and file transfers to set up a staging site.

Frequently Asked Questions

Next, let’s see some frequently asked questions regarding this topic.

Conclusion

WordPress Debug Log can significantly enhance your ability to manage and troubleshoot your WordPress site.

Whether you’re a developer refining code or an administrator ensuring site stability, the insights gained from this log are invaluable.

Remember, while debugging is crucial, it should be used judiciously, especially on live sites, to maintain performance and security.

By implementing the tips and best practices we’ve discussed, you’ll be well-equipped to keep your WordPress site running smoothly, catching and resolving issues before they impact your users.

Embrace the debug log as a tool for continuous improvement and site optimization. Keep learning and debugging, and keep your WordPress site at its best.

Have you found this article useful?

If you did, please share this with your friends and fellow bloggers. The article will also help them master the WordPress debug log and stay away from conflicts.

Don’t forget to follow our YouTube channel to stay updated on our latest news and content!