Andy Fragen

This plugin sets the following debug constants in <code>wp-config.php</code> on plugin activation and removes them on plugin deactivation. Any errors will result in a PHP Exception being thrown. Debug constants per <a href="https://developer.wordpress.org/advanced-administration/debug/debug-wordpress/" rel="nofollow ugc">Debugging in WordPress</a>.
Default settings:
<pre><code>define( 'WP_DEBUG_LOG', true );
define( 'SCRIPT_DEBUG', true );
define( 'SAVEQUERIES', true );
</code></pre>
  
 @ini_set( ‘display_errors’, 1 ); is set when the plugin is active. <code>WP_DEBUG</code> is set to true when the plugin is first run, thereafter it can be turned off in the Settings.
The Settings page allows the user to set the following.
<pre><code>define( 'WP_DEBUG', true ); // Default on initial plugin installation.
define( 'WP_DEBUG_DISPLAY', false ); // Default when not declared is true.
define( 'WP_DISABLE_FATAL_ERROR_HANDLER', true ); // WordPress 5.2 WSOD Override.
</code></pre>
When the plugin is deactivated best efforts are made to re-add pre-existing constants to their former state. When the plugin is activated the default settings and any saved settings are restored.
This plugin uses the <a href="https://github.com/wp-cli/wp-config-transformer" rel="nofollow ugc">wp-cli/wp-config-transformer</a> command for writing constants to <code>wp-config.php</code>.
<a href="https://github.com/norcross/debug-quick-look" rel="nofollow ugc">Debug Quick Look</a> from Andrew Norcross is included with this plugin to assist in reading the debug.log file. If you already have this plugin installed you should delete it when WP Debugging is not active.
<a href="https://wordpress.org/plugins/query-monitor/" rel="ugc">Query Monitor</a> and <a href="https://wordpress.org/plugins/debug-bar/" rel="ugc">Debug Bar</a> plugins are optional dependencies to aid in debugging and troubleshooting. The notice for installation will recur 45 days after being dismissed.
If you have a non-standard location for your <code>wp-config.php</code> file you can use the filter <code>wp_debugging_config_path</code> to return the file path for your installation.
The filter <code>wp_debugging_add_constants</code> allows the user to add constants to <code>wp-config.php</code>.
The filter returns an array where the key is the name of the constant and the value is an array of data containing the value as a string and a boolean to indicate whether or not the value should be passed without quotes.
<pre><code>$my_constants = [
 'my_test_constant' =>
 [
 'value' => 'abc123',
 'raw' => false,
 ],
 'another_test_constant' => [ 'value' => 'true' ],
];
</code></pre>
The <code>value</code> option contains the constant’s value as a string.
The <code>raw</code> option means that instead of placing the value inside the config as a string it will become unquoted. The default is <code>true</code>. Set as <code>false</code> for non-boolean values.
Example:
<pre><code>add_filter(
 'wp_debugging_add_constants',
 function( $added_constants ) {
 $my_constants = [
 'my_test_constant' => [
 'value' => '124xyz',
 'raw' => false,
 ],
 'another_test_constant' => [ 'value' => 'true' ],
 ];
 return array_merge( $added_constants, $my_constants );
 },
 10,
 1
);
</code></pre>
This will create the following constants.
<pre><code>define( 'MY_TEST_CONSTANT', '124xyz' );
define( 'ANOTHER_TEST_CONSTANT', true );
</code></pre>
<h3>Development</h3>
PRs are welcome against the <a href="https://github.com/afragen/wp-debugging" rel="nofollow ugc">develop branch on GitHub</a>.

WP Debugging

This helps me support customers and get better debugging information about errors happening on their site without having to ask for sensitive login info. Simple and does a great job, I've used it or recommended it a dozen times in the last month.

Great support tool

I can't tell you the number of times I've had to handle a support request that involved a white screen. Thank you, @afragen, for building this awesome tool to help define constants for a file that isn't easily accessible without passing around credentials.

Super Handy!

Thanks for the useful plugin, we're going to start recommending this to our customers.

Useful Plugin

Thank you for this useful and beautiful plugin, helps me a lot.

Very useful

Quick access to the log files speeds up development!

Great plugin

With this plugin it's at last possible to debug a remote site wihtout having access to the cpanel!

Very useful!


Every time I come across an obscure problem on WordPress sites, I start looking for it by installing this plugin.Thanks to the developers for a great tool!


Perfect tool for debug.

Yet another one of your plugins that I love and use all the time!  Thank you.  (Side note: is there a place to buy you a coffee or donate for your time?)

Another great debugging plugin

A support/troubleshooting plugin for WordPress.

Glimbyte

Stop editing wp-config.php every time you need to debug your WordPress site.
Developer Debug Mode lets you toggle all WordPress debug constants directly from your dashboard with beautiful toggle switches. Changes save automatically — no clicking save buttons, no FTP access needed, no risk of syntax errors in your config file.
<h4>🎯 The Problem This Plugin Solves</h4>
Every WordPress developer knows the pain:
<ol>
<li>Something breaks on your site</li>
<li>You need to enable WP_DEBUG to see the error</li>
<li>You open FTP/File Manager, find wp-config.php, edit it carefully</li>
<li>Debug the issue</li>
<li>Remember to turn debug off before visitors see ugly error messages</li>
<li>Repeat next time something breaks</li>
</ol>
Developer Debug Mode eliminates steps 2-5 entirely. Toggle debug on, find the error, toggle off. Done in seconds.
<h4>✨ Key Features</h4>
One-Click Debug Toggles 
Control all six WordPress debug constants from a clean, modern interface:
<ul>
<li>WP_DEBUG — Master switch for WordPress debugging</li>
<li>WP_DEBUG_LOG — Save errors to wp-content/debug.log</li>
<li>WP_DEBUG_DISPLAY — Show errors on screen (careful on production!)</li>
<li>SCRIPT_DEBUG — Use unminified core CSS/JS files</li>
<li>SAVEQUERIES — Log database queries for performance analysis</li>
<li>WP_DISABLE_FATAL_ERROR_HANDLER — See raw PHP fatal errors instead of recovery mode</li>
</ul>
Admin Bar Quick Toggle (New in 1.2.0!) 
Toggle any debug constant directly from the WordPress admin bar — no need to visit the settings page. Perfect for quick debugging sessions.
Built-in Debug Log Viewer 
View, search, download, and clear your debug.log without leaving WordPress:
<ul>
<li>Color-coded entries (fatal, error, warning, notice)</li>
<li>Search with highlighting</li>
<li>Auto-refresh option for real-time monitoring</li>
<li>One-click download and clear</li>
</ul>
Auto-Save Technology 
Changes save instantly as you toggle. No save button, no page refresh, no waiting.
Frontend Debug Warning 
A tasteful notification bar appears when WP_DEBUG_DISPLAY is active, reminding you to turn it off before visitors see error messages.
Cross-Tab Synchronization 
Toggle debug in one browser tab and watch other open tabs update instantly.
Automatic Backups 
Every change creates a backup of wp-config.php. The plugin keeps the 5 most recent backups, so you can always recover if something goes wrong.
<h4>🔧 Perfect For</h4>
<ul>
<li>Theme developers debugging template issues</li>
<li>Plugin developers testing new code</li>
<li>Site administrators troubleshooting problems</li>
<li>Agencies managing multiple client sites</li>
<li>Freelancers who need quick debugging without FTP access</li>
<li>Anyone tired of manually editing wp-config.php</li>
</ul>
<h4>💡 Why Choose Developer Debug Mode?</h4>
Unlike other debug plugins, we focus on user experience:
✅ Instant toggles — No save buttons, changes apply immediately 
✅ Visual feedback — Clear status indicators show exactly what’s enabled 
✅ Admin bar access — Toggle debug from anywhere in WordPress 
✅ Production-safe — Frontend warnings prevent accidentally exposing errors 
✅ Modern design — Beautiful UI that fits naturally in your dashboard 
✅ Lightweight — No bloat, loads only where needed
<h4>🔒 Built With Security In Mind</h4>
<ul>
<li>Capability checks ensure only administrators can change settings</li>
<li>Nonce verification on all AJAX requests</li>
<li>Automatic wp-config.php backups before every change</li>
<li>No data sent to external servers</li>
<li>Clean uninstall removes all plugin data</li>
</ul>
<h4>📚 Debug Constants Explained</h4>
Not sure what each constant does? Here’s a quick guide:
WP_DEBUG 
The master switch. When enabled, WordPress will display PHP errors, notices, and warnings. Required for the other debug constants to work.
WP_DEBUG_LOG 
Saves all debug messages to <code>/wp-content/debug.log</code>. Essential for debugging issues that happen in the background (AJAX, cron jobs, REST API).
WP_DEBUG_DISPLAY 
Shows errors directly on your web pages. Useful during development but never enable on production — it can expose sensitive information to visitors.
SCRIPT_DEBUG 
Forces WordPress to use the development versions of core CSS and JavaScript files instead of minified versions. Helpful when debugging scripts.
SAVEQUERIES 
Stores database queries in a global array for later analysis. Useful for identifying slow queries but adds overhead — disable when not needed.
WP_DISABLE_FATAL_ERROR_HANDLER 
Disables WordPress’s “recovery mode” so you see the actual PHP fatal error instead of “There has been a critical error on this website.”
<h4>🤝 Support & Documentation</h4>
Need help? We offer:
<ul>
<li>Free Support — Post in the <a href="https://wordpress.org/support/plugin/developer-debug-mode/" rel="ugc">WordPress.org support forum</a></li>
<li>Documentation — Visit <a href="https://glimbyte.ie" rel="nofollow ugc">glimbyte.ie</a> for guides and tutorials</li>
<li>Express Support — Fast turnaround for urgent issues via <a href="https://glimbyte.ie/support" rel="nofollow ugc">glimbyte.ie/support</a></li>
</ul>
<h4>🌐 Works Great With</h4>
<ul>
<li>Query Monitor — Use alongside for deeper debugging</li>
<li>Debug Bar — Compatible with Debug Bar and its add-ons</li>
<li>Any caching plugin — Clear cache after toggling debug constants</li>
<li>Managed WordPress hosts — Works on most hosts including Kinsta, WP Engine, SiteGround</li>
</ul>
<h3>Credits</h3>
Developed with ❤️ by <a href="https://glimbyte.ie" rel="nofollow ugc">Glimbyte</a> — WordPress Development & Support.
Special thanks to the WordPress community for feedback and suggestions.
<h3>Privacy Policy</h3>
Developer Debug Mode does not collect, store, or transmit any personal data. All settings are stored locally in your WordPress database and wp-config.php file.
The optional support contact form (available in the plugin settings) sends data directly to Glimbyte’s support team. This data is handled according to <a href="https://glimbyte.ie/privacy" rel="nofollow ugc">Glimbyte’s Privacy Policy</a>.
<h3>Additional Info</h3>
<h4>Contribute</h4>
Found a bug or have a feature request? We’d love to hear from you!
<ul>
<li>Support Forum: <a href="https://wordpress.org/support/plugin/developer-debug-mode/" rel="ugc">wordpress.org/support/plugin/developer-debug-mode</a></li>
<li>Website: <a href="https://glimbyte.ie" rel="nofollow ugc">glimbyte.ie</a></li>
</ul>
<h4>Translations</h4>
Want to help translate Developer Debug Mode into your language? Visit <a href="https://translate.wordpress.org/projects/wp-plugins/developer-debug-mode/" rel="nofollow ugc">translate.wordpress.org</a> to contribute.

Developer Debug Mode


Well-designed plugin! Minimalist UI, perhaps a bit dated, but performs its task very well.


Amazing

Toggle WordPress debug mode instantly. No wp-config.php editing needed. Features auto-save, admin bar quick toggle, and debug log viewer.

WP Debugging vs Developer Debug Mode