Forge12 Interactive GmbH

F12 Profiler analyzes your WordPress site comprehensively and delivers concrete, prioritized recommendations to improve load times. The plugin combines server diagnostics, asset analysis, database optimization, and plugin impact assessment in a modern, clean interface.
<h4>Features</h4>
Analysis & Diagnostics
<ul>
<li>Server analysis (PHP, MySQL, OPcache, web server, SSL, HTTP/2, compression)</li>
<li>Automatic site crawler with load time measurement (desktop & mobile)</li>
<li>Asset analysis (CSS, JS, images) with optimization potential</li>
<li>OPcache status & configuration recommendations</li>
<li>PHP profiler (runtime, queries, hooks, plugin ranking, culprit analysis)</li>
<li>Plugin impact analysis (assets, hooks, queries per plugin)</li>
<li>PageSpeed Insights integration (Lighthouse Scores + Core Web Vitals + CrUX)</li>
<li>Performance score with 6 weighted categories (A-F grades, trend delta)</li>
<li>Recommendation engine with automatic optimization suggestions</li>
</ul>
Optimization Tools
<ul>
<li>Lazy Loading (images and iframes)</li>
<li>Font Display Optimization (font-display: swap/optional/fallback/block)</li>
<li>Script Defer Manager (automatic defer for scripts with exclusion list)</li>
<li>Auto Image Dimensions (prevents Layout Shifts / CLS)</li>
<li>HTML Minification (whitespace, comments, empty attributes)</li>
<li>CSS/JS Minification (file-based cache)</li>
<li>WordPress Bloat Removal (emojis, embeds, Dashicons, jQuery Migrate, XML-RPC, Heartbeat, and more)</li>
<li>Browser Cache (.htaccess-based)</li>
<li>DNS Prefetch & Preconnect (domain detection from asset scan)</li>
<li>Database Analysis (8 categories with detail view)</li>
<li>Autoload Manager (granular wp_options management)</li>
<li>Background Asset Scanner with conflict detection</li>
<li>File-based Page Cache with TTL and URL exclusion (Pro)</li>
<li>CSS/JS Asset Manager – disable, defer, async per page or globally (Pro)</li>
<li>Conditional Loading – shortcode, block, regex, archive, login status, post type, plugin (Pro)</li>
<li>Smart auto-suggestions with source-based plugin detection after full scan (Pro)</li>
<li>Asset Preload Manager – Link headers for critical assets (Pro)</li>
<li>Critical CSS Generator & Applier – above-the-fold CSS per template (Pro)</li>
<li>Unused CSS Removal – per page template, safelist, regex safelist (Pro)</li>
<li>WebP Image Conversion with batch queue and backup (Pro)</li>
<li>LQIP Image Placeholders – 20px blur-up previews with IntersectionObserver (Pro)</li>
<li>Preload Key Requests – LCP images, fonts, critical resources (Pro)</li>
<li>Script Delay – delays third-party JS until first user interaction (Pro)</li>
<li>Local Google Fonts – GDPR-compliant WOFF2 self-hosting (Pro)</li>
<li>YouTube/Vimeo Facade – thumbnail + play button instead of iframe (Pro)</li>
<li>Database Cleanup – one-click per category or bulk action (Pro)</li>
<li>Redis Object Cache Management – drop-in installation/removal (Pro)</li>
<li>Scheduled Crawls & Cleanups via WP-Cron (Pro)</li>
<li>Performance Budgets with email/webhook notifications (Pro)</li>
<li>Settings Import/Export as JSON (Pro)</li>
<li>One-Click Optimizer – automated optimization with backup & restore (Pro)</li>
<li>License Management with activation/deactivation (Pro)</li>
</ul>
User Interface
<ul>
<li>Modern iOS-style design system</li>
<li>React 18 + TypeScript SPA</li>
<li>30+ pages/tools with dedicated configuration</li>
<li>Context-sensitive info sections on all pages</li>
<li>Pro features visible with lock icon and upgrade prompt</li>
</ul>
<a href="https://www.forge12.com/f12-profiler-pro/" rel="nofollow ugc">Get F12 Profiler Pro</a>
<h4>System Requirements</h4>
<ul>
<li>WordPress 6.0 or higher</li>
<li>PHP 8.0 or higher</li>
<li>MySQL 5.7 / MariaDB 10.3 or higher</li>
</ul>

F12 Profiler

Excellent! After P3 doesn’t work with PHP7+ anymore, F12 seems finally the one stepping in to fill that gap.

Update [18-Jun-19]. After some small contributions of mine to the dev efforts, the plugin developer has decided to add me to the team, long after this review was written.

Finally an alternative to P3

Comprehensive WordPress performance analysis with crawling, load time measurement, server diagnostics, and integrated optimization tools. Free.

Viktor Szépe

<h4>Only for development!</h4>
<h4>Now with OPcache memory consumption support</h4>
This plugin dumps the colorized filenames and memory consumptions or file sizes after the normal WordPress HTML output, after the closing html tag. This generates invalid HTML but gives you an overview of loaded plugins and the current theme.
What’s running lists all files parsed and executed by the PHP engine. It can be used for plugin or theme refactoring.
<h4>Now you can highlight your own plugin and theme</h4>
Provide a part of its path in wp-config.php:
<pre><code>define( 'WHATS_RUNNING_HIGHLIGHT', 'wp-content/plugins/my-plugin' ); </code></pre>
<h4>Color codes</h4>
<ul>
<li>your code is highlighted with YELLOW background</li>
<li>plugin files are in BLUE</li>
<li>themes files are in ORANGE</li>
<li>files in the wp-includes directory are in GREEN</li>
<li>files in the wp-admin directory are in GREY</li>
<li>all other files are in RED</li>
<li>VIOLET bar after the filename represents the file size ( 0.5 kB/px )</li>
<li>DARK MAGENTA bar after the filename represents the OPcache memory consumption ( 1 kB/px )</li>
</ul>
<h4>Links</h4>
You can watch <a href="https://core.trac.wordpress.org/ticket/28364" rel="nofollow ugc">WP core bug #28364</a> to get more information about <a href="https://github.com/szepeviktor/WPHW/blob/master/wp-entry-points.md" rel="nofollow ugc">WordPress entry points</a>.
You can find some documentaion here what makes a WordPress plugin efficient: https://github.com/szepeviktor/WPHW
Development of this plugin goes on on <a href="https://github.com/szepeviktor/whats-running" rel="nofollow ugc">GitHub</a>.

What's running

Lists WordPress require() calls mainly for plugin code refactoring.

F12 Profiler vs What's running