A guide on how to Debug WordPress

Encountering errors on your WordPress website can be daunting. These issues might present as HTML error codes, the infamous white screen of death, or unexpected behaviour in your site’s functionality. Debugging is an essential skill in managing and maintaining a healthy WordPress website. It involves identifying, isolating, and fixing bugs or errors within your WordPress installation. To streamline the debugging process and make it more efficient, follow this expanded guide which includes key steps and additional troubleshooting tips.

Step 1: Enable WP_DEBUG

WP_DEBUG is a powerful WordPress feature designed for debugging your site. It allows you to see the underlying errors behind issues on your site by displaying error messages that would otherwise be hidden. However, caution is advised when using WP_DEBUG on a live site, as it can reveal sensitive information to visitors. It’s best to turn this feature on temporarily while troubleshooting.

How to Enable WP_DEBUG

  1. Access your website’s files via FTP or your web host’s file manager.
  2. Locate the wp-config.php file at the root of your WordPress installation.
  3. Find the line that says /* That's all, stop editing! Happy publishing. */.
  4. Just above that line, insert the following code:

    define( 'WP_DEBUG', true );
    define( 'WP_DEBUG_LOG', true );
    define( 'WP_DEBUG_DISPLAY', false );
    @ini_set( 'display_errors', 0 );
  5. Save your changes. Errors will now be logged to the wp-content/debug.log file.

Step 2: Enable PHP Error Logging

Since WordPress is built on PHP, enabling PHP error logging is crucial for identifying any server-side issues. This complements WP_DEBUG by ensuring all PHP errors are captured, offering a broader view of potential issues.

Enabling PHP Error Logging

  1. Access your php.ini file, which is typically found in your server’s PHP installation directory. On shared hosting, you may need to contact your hosting provider for assistance.
  2. Look for the line ;error_log = php_errors.log and remove the semicolon (;) to uncomment it.
  3. Change it to specify a path for the log file, for example:

    error_log = /path/to/your/webroot/wp-content/php_errors.log
  4. Save your changes and restart your web server.

Step 3: Utilise a Staging Environment

A staging site is an exact replica of your live website, which allows you to test changes or troubleshoot issues without risking the stability and performance of your live site. Most reputable hosting services offer staging environments, making it easier to debug and test updates safely.

Setting Up a Staging Site

  1. Check with your hosting provider for staging capabilities and follow their setup process.
  2. Once your staging site is ready, replicate the issue you’re experiencing on the live site.
  3. Debug freely, knowing your live site remains unaffected.

Additional Troubleshooting Tips

Check for Plugin Conflicts

  1. Deactivate all plugins.
  2. Reactivate them one by one to identify if a plugin is the source of your issue.

Switch to a Default Theme

  1. Sometimes, themes can cause conflicts.
  2. Switching to a WordPress default theme like Twenty Twenty-One can help determine if your theme is the problem.

Review Recent Changes

  1. Think back to any recent changes made before the issue appeared.
  2. Reverting these changes can sometimes resolve the problem.

Consult Error Logs

  1. Regularly check the wp-content/debug.log and your PHP error logs for clues that can help identify the cause of the problem.

Update Everything

  1. Ensure all plugins, themes, and WordPress itself are up to date.
  2. Compatibility issues often arise from outdated software.

By following these steps and tips, you can effectively debug your WordPress site, leading to quicker resolutions and a more stable, efficient website. Remember, careful and methodical troubleshooting is key to identifying and solving issues within WordPress.