What are some advanced features of Query Monitor?

Query Monitor includes some advanced features such as debugging of Ajax calls, REST API calls, user capability checks, and full support for block themes and full site editing. It includes the ability to narrow down much of its output by plugin or theme, allowing you to quickly determine poorly performing plugins, themes, or functions.

What information does Query Monitor show for each page load?

Query Monitor shows information such as database queries, template hierarchy, PHP errors, usage of deprecated functionality, blocks and associated properties, matched rewrite rules, enqueued scripts and stylesheets, language settings, HTTP API requests, user capability checks, environment information, conditional functions, transients, and usage of switch_to_blog() and restore_current_blog() on Multisite installations.

What additional information does Query Monitor provide?

Query Monitor provides additional information such as call stack for redirects, debugging information in headers for jQuery-initiated Ajax requests and PHP errors, and performance information and PHP errors in headers for authenticated WordPress REST API requests.

Who can view Query Monitor's output by default?

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

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Query Monitor

Q: What is Query Monitor?

Query Monitor is the developer tools panel for WordPress. It enables debugging of database queries, PHP errors, hooks and actions, block editor blocks, enqueued scripts and stylesheets, HTTP API calls, and more.

Query Monitor is the developer tools panel for WordPress.

Rating:

4.9

Active Installations:

200000+

Last Updated:

Sep 08, 2025

WordPress Version:

6.0 or higher

Tested up to:

6.8.3

Features Download’s trend Changelog Reviews

Powerful WordPress debugging

Query Monitor offers a comprehensive set of developer tools for WordPress, including debugging of database queries, PHP errors, hooks and actions, block editor blocks, enqueued scripts and stylesheets, HTTP API calls, and more.

Identify performance bottlenecks

Quickly determine poorly performing plugins, themes, or functions with Query Monitor.

Identify performance issues

With Query Monitor, you can quickly determine poorly performing plugins, themes, or functions by narrowing down its output by plugin or theme. It shows aggregate database queries grouped by the responsible components, making it easy to identify and fix performance bottlenecks.

Advanced debugging features

Query Monitor goes beyond basic debugging and includes advanced features such as debugging Ajax calls, REST API calls, user capability checks, and full support for block themes and full site editing. It provides detailed information and debugging tools for a wide range of development scenarios.

Author’s Site

3.20.0 (7 September 2025)

Defers loading of translation files as late as possible to minimise the chance of triggering the Translation loading for the query-monitor domain was triggered too early error
Implements some initial compatibility tweaks for the upcoming PHP 8.5

3.19.0 (23 July 2025)

Adds Guzzle middleware support for logging HTTP client requests.
Fixes plugin conflicts caused by the global qm JavaScript variable by renaming it to QueryMonitorData.
Corrects invalid HTML markup where <th> elements were closed with </td> tags.

3.18.0 (16 June 2025)

Adds more comprehensive handling of HTTP API requests which were overridden by the pre_http_request filter.
Corrects the handling of suppressed PHP errors on both PHP 7 and PHP 8.
Confirms support for WordPress 6.8.

3.17.2 (4 February 2025)

Reinstates the “Blocks” panel

3.17.1 (2 February 2025)

Prevents use of the deprecated E_STRICT constant in PHP 8.4.
Avoids use of the deprecated setted_transient and setted_site_transient actions in WordPress 6.8.
Skips showing the _load_textdomain_just_in_time notices when they’re caused by Query Monitor itself.
Uses more appropriate formatting for a fatal error in REST API and Ajax contexts.

3.17.0 (27 November 2024)

Support for WordPress 6.7.
Support for PHP 8.4.
Inline scripts are now output using wp_print_inline_script_tag() so a Content Security Policy can be fully implemented.
Various improvements and fixes.

3.16.4 (25 July 2024)

Confirms support for WordPress 6.6.

3.16.3 (22 May 2024)

Prevents an infinite loop when logging doing it wrong calls and deprecated calls.
Removes a global from query-monitor.php

3.16.2 (22 May 2024)

Fixes another issue with the PHP autoloader in 3.16.0 and 3.16.1 that was crashing some sites

3.16.1 (22 May 2024)

Fixes an issue with the PHP autoloader in 3.16.0 that was crashing some sites

Earlier versions

For the changelog of earlier versions, refer to the releases page on GitHub.

db.php is integral requirement of WP Studio !!

By ademorg on October 26, 2025

Switched to WP studio as an easy solution to spinup a quick site for testing/cursor on my space limited macbook air - unfortunately it uses db.php for its sqllite based WP site databases so plugin is unable to function.

Any plans in future to make amendments to this plugin to use anything other than db.php ??

Haven't checked to see if WP Studio boys are planning to allow us to use mySQL/mariadb so that we can utilise this for plugin for plugin/theme development.

Adrian

great tool

By sohaus on September 23, 2025

thank you!

Thanks for this.

By surviving404 on September 2, 2025

It is a fantastic plugin, been using this for long.

Essential for theme and plugins developers

By Attila Bogozi (waaab) on July 23, 2025

Probably the best tool for theme and plugins developers.

Great! It shows "Doing it Wrong" in admin

By lunat on June 1, 2025

It shows "Doing it Wrong" in admin. It surprised me positively.

A.M.A.Z.I.N.G.

By nspirov on May 19, 2025

This thing is AMAZING! Thank you for this great tool.

Totally Crashed Our Backend

By ChrisMonty on February 4, 2025

This plugin totally crashed the Admin area of our website. We had to contact our hosting provider and ask them to delete the plugin's files.

vvvvvvvvvvvvvvvvery good and useful

By mmkh on January 10, 2025

vvvvvvvvvvvvvvvvery good and useful

Very impressive

By nmxde on January 8, 2025

A must if you want to know what your Wordpress is doing.

Essential for Debugging and Performance Monitoring

By NDV Comunicazione - Sviluppo (ndvcomunicazionesviluppo) on December 4, 2024

Query Monitor is an incredibly useful tool for developers and site administrators. It provides detailed insights into database queries, page load times, and resource consumption, making it a must-have for debugging and performance optimization.

I particularly appreciate how it highlights potential errors in the code and plugins during development, saving time and effort in troubleshooting. Its intuitive interface and in-depth reports make identifying issues straightforward.

Overall, it’s a fantastic plugin that I highly recommend to anyone building or maintaining WordPress websites.

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