Brett

Frontend Features: 
 – adds a toolbar to the bottom of WordPress pages that will show meaningful information that helps developers to create optimized WordPress sites. 
 – Info includes SQL queries, query vars, peak memory usage, and a filetrace.
Backend Features: 
 – Provides a very basic checklist with suggestions for development. 
 – Shows basic server stats and information 
 – phpInfo 
 – WP rewrite rules (coming soon)

Developer Toolbar

Adds easy to access data for developers, including a fixed toolbar to the bottom of pages that shows query data and memory usage among other data.

wpaluchmits

MITS Profiler is a tool by <a href="https://mits.pl" rel="nofollow ugc">MITS</a> — a WordPress and WooCommerce agency based in Poland. It adds a diagnostic bar to any page by appending <code>?mits_prof=1</code> to the URL. It captures timing data from the moment PHP starts and presents it in a dark-themed panel at the bottom of the page — visible only to logged-in administrators.
Tabs included:
<ul>
<li>Timeline — absolute and relative timing between WordPress lifecycle hooks (plugins_loaded → init → wp_head → wp_footer)</li>
<li>Hooks — top 50 slowest action/filter hooks with total time and call count</li>
<li>Options — most-queried WordPress options + full autoload audit with sizes</li>
<li>Plugins — loaded PHP file sizes per plugin (proxy for load time)</li>
<li>Assets — all enqueued scripts and styles, external ones highlighted</li>
<li>HTTP — outgoing wp_remote_* requests with response time and status</li>
<li>SQL — all database queries with slow-query highlighting (requires SAVEQUERIES)</li>
<li>PHP — PHP version, OPcache status and hit rate, memory and execution limits</li>
</ul>
Key features:
<ul>
<li>Zero HTTP loopback — works behind Cloudflare, reverse proxies and strict firewall rules</li>
<li>No external dependencies or requests</li>
<li>Admin-only: the panel and all data are never shown to guests</li>
<li>Export to JSON or CSV for offline analysis</li>
<li>Works on front-end pages, WooCommerce pages, and WP Admin</li>
</ul>
SQL query logging requires adding the following to <code>wp-config.php</code>:
<pre><code>define('SAVEQUERIES', true);
</code></pre>

MITS Profiler

Lightweight WordPress performance profiler. No HTTP loopback requests — works behind Cloudflare and any proxy.

Developer Toolbar vs MITS Profiler