Query Monitor for WordPress

Blocks and associated properties within post content and within full site editing (FSE).

Matched rewrite rules, associated query strings, and query vars.

Enqueued scripts and stylesheets, along with their dependencies, dependents, and alerts for broken dependencies.

Language settings and loaded translation files (MO files and JSON files) for each text domain.

HTTP API requests, with response code, responsible component, and time taken, with alerts for failed or erroneous requests.

User capability checks, along with the result and any parameters passed to the capability check.

Environment information, including detailed information about PHP, the database, WordPress, and the web server.

The values of all WordPress conditional functions such as is_single(), is_home(), etc.

Transients that were updated.

Usage of switch_to_blog() and restore_current_blog() on Multisite installations.

In addition:

Whenever a redirect occurs, Query Monitor adds an HTTP header containing the call stack, so you can use your favourite HTTP inspector or browser developer tools to trace what triggered the redirect.

The response from any jQuery-initiated Ajax request on the page will contain various debugging information in its headers. PHP errors also get output to the browser’s developer console.

The response from an authenticated WordPress REST API request will contain an overview of performance information and PHP errors in its headers, as long as the authenticated user has permission to view Query Monitor’s output. An an enveloped REST API request will include even more debugging information in the qm property of the response.

By default, Query Monitor’s output is only shown to Administrators on single-site installations, and Super Admins on Multisite installations.

In addition to this, you can set an authentication cookie which allows you to view Query Monitor output when you’re not logged in (or if you’re logged in as a non-Administrator). See the Settings panel for details.

Browser extension Query Monitor is also available as an optional browser dev tools extension. This is an alternative to using the in-page panel that gets output into the admin toolbar.

Using the browser extension has some advantages over the in-page panel:

The Query Monitor panel doesn’t take up space within the page you are inspecting

The panel can be resized, undocked, and moved around like any other developer tools panel

Information about the Query Monitor browser extension can be found here.

Other Plugins I maintain several other plugins for developers. Check them out:

User Switching provides instant switching between user accounts in WordPress.

WP Crontrol lets you view and control what’s happening in the WP-Cron system

Thanks The time that I spend maintaining this plugin and others is in part sponsored by:

Automattic

ServMask

WP Staging

All my kind sponsors on GitHub

Privacy Statement Query Monitor is private by default and always will be. It does not persistently store any of the data that it collects. It does not send data to any third party, nor does it include any third party resources. Query Monitor’s full privacy statement can be found here.

Accessibility Statement Query Monitor aims to be fully accessible to all of its users. Query Monitor’s full accessibility statement can be found here.