5 Top WordPress Debug Plugins

If you are a developer or WordPress site administrator, then you already know that a WordPress debug plugin is one of the most essential tools you can have in your site management arsenal.

This is because WordPress websites are generally prone to errors, given the multiple elements, such as core software, themes, plugins, and custom code, that need to work together. 

WordPress debug plugins help you quickly detect and resolve errors that occur on your site, ensuring it remains up and running smoothly at all times.

In this article, we will thoroughly examine the importance of WordPress debug plugins for site management and then present the top options you can use to troubleshoot errors on your site. 

Table of Contents

• What Does a WordPress Debug Plugin Do?
• 4 Top WordPress Debug Plugins
  • Query Monitor
  • Debug Bar
  • Debug Log Manager
  • Error Log Monitor
• 4 Top WordPress Debug Plugins – Final Thoughts

What Does a WordPress Debug Plugin Do?

To explain what WordPress debug plugins do, here’s a simple analogy: WordPress debug plugins are to troubleshooting what a washing machine is to laundry. Although you can wash clothes by hand, it takes much more of your valuable time that could be better spent on more important tasks. That’s why most people prefer using a washing machine.

Similarly, debugging errors on a WordPress site can either be done manually or with a WordPress debug plugin. Manual debugging requires more time and effort, especially when working on multiple sites. WordPress debug plugins, on the other hand, make the process faster and easier by streamlining error diagnosis.

The manual method of debugging WordPress errors involves adding WP_DEBUG constants to your wp-config.php file, accessing the debug.log file via FTP, and reviewing your error logs with a text file reader. Another manual approach is to deactivate all plugins and themes one by one, then reactivate them to determine which one may be triggering an error.

In contrast, a WordPress debug plugin lets you enable debug mode with a single click and view your WordPress error logs in formatted tables that are easy to filter. This allows you to identify and resolve issues on your website quickly. 

Some WordPress debug plugins even take it a step further by offering advanced insights into other aspects of your site, such as HTTP API calls, database queries and their performance, hooks and actions fired during page loads, enqueued scripts and stylesheets, etc.

Ultimately, a good WordPress debug plugin will make debugging and troubleshooting errors on your WordPress site much faster by eliminating time-consuming manual steps and providing clear insights through a user-friendly interface. 

With that being said, let’s now take a look at the 4 top WordPress debug plugins that you can consider for your site’s debugging needs.

5 Top WordPress Debug Plugins

There are many WordPress debug plugins available in the WordPress plugin repository. However, they all have different features and capabilities. We tested several options, and here are the top four we recommend.

1. WP Debug Toolkit

WP Debug Toolkit is a premium debugging plugin that offers an easy and reliable way to troubleshoot WordPress projects. What sets WP Debug Toolkit apart is its independent error log viewer app that functions even when WordPress crashes or you get locked out of your admin dashboard. This ensures you can always access your error logs and regain control of your site, no matter what happens.

The plugin makes managing debug constants effortless by letting you activate debug mode with a single click without the need to manually edit the wp-config.php file. Once enabled, the log viewer monitors all PHP and WordPress errors in real-time, featuring built-in filters to highlight and quickly locate specific issues on your site.

One of WP Debug Toolkit’s standout features is its integrated file viewer, which shows you the exact location where an error occurred, giving you complete context for faster troubleshooting. If your site ever crashes, the crash recovery system lets you temporarily disable all plugins and themes, making it easy to log back in without the usual trial-and-error process.

Key Features

• Real-Time Error Monitoring: Track PHP and WordPress errors as they happen with instant notifications.
• Advanced Filtering: Include or exclude logs by keyword, error level, time, or source to focus on what matters.
• Integrated File Viewer: Examine the full context of errors beyond just reading the log entries.
• Modern User Interface: Clean, intuitive design that makes debugging less intimidating for users of all skill levels.
• Keyboard Shortcuts: Navigate through logs efficiently using built-in keyboard shortcuts.
• Error Highlighting: Quickly identify different error types and their severity at a glance.

Price

WP Debug Toolkit is a premium plugin with pricing starting at $59 for a single-site license.

2. Query Monitor

Query Monitor is a feature-rich WordPress debugging plugin that does much more than just monitor database queries, despite its name. With this plugin, you can also debug PHP errors, HTTP API calls, hooks and actions, enqueued scripts and stylesheets, among other things.

The Query Monitor user interface can be accessed from both the front end and back end of your website. It initially shows a summary of key insights for the current page as a menu within the admin toolbar. The summary includes page generation time, peak memory usage, total SQL query time in seconds, and the total number of SQL queries.

Clicking the summary opens the full Query Monitor interface, allowing you to explore any of the many insights the plugin offers. You will see options for some of its more advanced features, such as debugging Ajax calls, performing user capability checks, and debugging REST API calls, among others.

One helpful feature of the Query Monitor plugin is its ability to group PHP errors and database queries by both the location or caller and the component (e.g., plugin, theme, or function) responsible for them. This helps you quickly identify the root cause of an issue on your site without having to scroll through endless lines of errors or queries.

By default, Query Monitor restricts access to its output to site administrators on single-site installs and super admins on multi-site networks. This is to prevent sensitive data from being exposed to unauthorized users. However, if you want to access the insights provided by Query Monitor even when you’re not logged in or logged in as a non-admin user, the plugin allows you to set an authentication cookie for this purpose.

Key Features

• Database Queries: The Query Monitor plugin displays all database queries executed during the current page load, including the time each query takes, the number of affected rows, and alerts for slow, duplicate, or error-containing queries. Query details are organized by type, component, or calling function and can be filtered accordingly.
• PHP Errors: With Query Monitor, you can see all PHP warnings, notices, stricts, and deprecated errors, formatted neatly along with their component and call stack. When needed, it also shows a visible warning in the menu added to your admin toolbar.
• Hooks and Actions: View all hooks triggered during the current page request, along with their action callbacks, priorities, and components. Query Monitor allows you to filter actions by component or name.
• Theme: Query Monitor displays the template filename, complete template hierarchy, and names of all theme parts that were loaded or not loaded.
• HTTP API Requests: All server-side HTTP requests are displayed, including their response codes, call stacks, components, timeouts, response sizes, durations, and other metadata.
• User Capability Checks: With the Query Monitor plugin, you can see every user capability check performed, along with the result and any parameters passed during the check.
• Environment Information: View details about your site’s environment, including PHP info (such as memory limit and error reporting levels), MySQL or MariaDB details, WordPress and web server information, and more.
• Performance Profiling: Query Monitor can show basic performance profiling in the Timings panel using actions in your code.
• Authentication: Using Query Monitor’s authentication cookie, you can view the plugin’s output when you’re not logged in or when logged in as a user who normally cannot see Query Monitor’s output.

Price

Query Monitor is a free plugin and can be downloaded from the WordPress plugin repository.

3. Debug Bar

Debug Bar is a WordPress debugging plugin created and maintained by the WordPress.org community. It is a lightweight plugin that, by default, adds a debug menu to the upper-right corner of your admin bar. Clicking this menu shows the current page’s database queries, cache information, and other useful data.

Out of the box, Debug Bar provides only limited debugging information, primarily related to performance. To access more of its WordPress debugging features, it offers several add-ons, such as Debug Bar Actions and Filters, which display Actions and Filters attached to the current page; Debug Bar Console, which adds a PHP/SQL console to the debug bar; and Debug Bar Transients, which provides information about WordPress transients, among others.

However, note that the Debug Bar plugin does not include a feature to automatically enable WordPress debug mode. To do so, you will need to manually add the code below to your wp-config.php file:

define( 'WP_DEBUG', true );
define( 'SAVEQUERIES', true );

Key Features

• Database Query Information: Debug Bar tracks and displays all MySQL queries when SAVEQUERIES is enabled, helping you identify performance issues.
• Cache Information: The plugin shows details such as your site’s cache size, hits, misses, and group statistics.
• Actions & Filters Insights: The Debug Bar Actions and Filters add-on adds two new tabs to monitor actions and filters hooked to the current request.
• PHP Error Details: When WP_DEBUG is enabled, Debug Bar captures and displays PHP errors, warnings, and notices to facilitate troubleshooting.
• Add-Ons: Debug Bar offers various add-ons to extend its WordPress debugging capabilities, covering areas such as transients, constants, shortcodes, and remote requests.

Price

The Debug Bar plugin is available for free download from WordPress.org.

4. Debug Log Manager

The Debug Log Manager WordPress debugging plugin offers a simple and user-friendly error log management interface, making it easy to enable WordPress’s built-in debug mode. This allows you to log and view PHP, database, and JavaScript errors as needed without manually editing your site’s wp-config.php file.

Debug Log Manager takes a unique approach to creating and storing the debug.log file. Usually, this file is stored in the /wp-content/ folder of every WordPress site. To improve security, the plugin uses a custom file name and stores it in a non-default location within your WordPress directory.

When using the plugin for WordPress debugging, you can easily search or filter to find specific errors in the log entries, quickly identify the error source, including file path and line number, and directly view the files where PHP errors occurred.

You can also enable auto-refresh of WordPress error logs, disable logging of JavaScript errors, prevent changing the SCRIPT_DEBUG value in wp-config.php, and disable the processing of entries with non-UTC timezones.

Key Features

• Debug.log Security: The Debug Log Manager saves the debug.log file with a custom name and stores it in a non-default location, providing an extra layer of security.
• Centralized Error Logging: With Debug Log Manager, you can view logs for various types of errors on your site, including PHP, database, and JavaScript errors.
• Search Bar & Filters: The plugin features a search bar and filters to quickly browse log entries and locate specific errors that require urgent attention.
• Error Information Breakdown: Errors displayed in the Debug Log Manager interface are categorized by source, file path, and line number, allowing you to identify the source of an issue quickly.
• Auto-Refresh: An auto-refresh toggle is available for real-time error logging, so new log entries are shown without needing to manually refresh the page.
• Admin Bar Indicator: To prevent accidentally leaving error logging enabled, an admin bar indicator is included.
• Dashboard Widget: This feature provides immediate insights into the latest errors logged on your site, without requiring you to open the Debug Log Manager interface.

Price

Debug Log Manager is a free WordPress debug plugin and can be downloaded from the WordPress plugin repository.

5. Error Log Monitor

The Error Log Monitor WordPress Debug plugin is designed solely to display the latest log messages from your site’s PHP error log.

Its operation is quite simple. After installing the plugin on your site, a widget will appear on your admin dashboard that automatically shows the last 20 messages from your PHP error log. This widget can be customized with options to adjust the number of entries displayed, set up email notifications, and filter error types.

To access some of the more advanced features—such as an error log summary, stack traces for every error, warning, and notice, along with context for each logged error—you would need to upgrade to the pro version. 

Key Features

• PHP Error Tracking: The plugin displays the latest messages from your PHP error log, helping you stay on top of any new issues on your site.
• Email Notifications: With Error Log Monitor, you can set up email alerts to receive updates about the most recent logged errors.
• Error Log Deletion: The plugin offers an option to easily clear your log file after resolving logged errors.
• Supports Large Log Files: Error Log Monitor is optimized to perform well even with very large log files.

Price

Error Log Monitor is a freemium WordPress debugging plugin. The free version can be downloaded from WordPress.org. You can upgrade to the premium version, which costs $19 for a single-site license, through the plugin’s dashboard.

Top WordPress Debug Plugins – Final Thoughts

Although WordPress has built-in debugging features that can be manually enabled, accessed, and used for troubleshooting, it’s not the most efficient way to find and debug errors. 

WordPress debug plugins provide a more centralized and user-friendly way to view and manage the WordPress error log. They offer more detailed insights about your site, save time with search and filtering options, and lessen the chances of mistakes when editing the wp-config.php file. 

From our list, it’s clear that WP Debug Toolkit offers the most comprehensive and reliable debugging solution. Its independent log viewer, crash recovery system, and one-click debug activation make it the ideal choice for both casual users and developers who need dependable error access regardless of their site’s status.

Top WordPress Debug Plugins – Frequently Asked Questions

1. How to solve troubleshoot problems in WordPress?

Troubleshooting problems can be done by using reliable WordPress debug plugins, such as WP Debug Toolkit, which enable you to quickly identify conflicts with plugins, themes, WordPress core, or custom code. Once identified, you can easily fix the issue and get your site running smoothly again.

2. How to debug a WordPress site?

You can troubleshoot a WordPress site manually by setting values for the WordPress debug constants in your wp-config.php file as shown below. This allows you to access the debug.log file and review your error logs:

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

If you prefer not to deal with code, a better option for debugging is to use debug plugins, such as WP Debug Toolkit.

3. What are the risks of debug mode?

Debug mode can introduce security, performance, and operational risks if left enabled indefinitely. These risks include the disclosure of sensitive system information, data breaches, remote code execution, decreased site performance, and a poor overall experience for users.