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.

Artberri

WP XHProf Profiler plugin is an easy way to profile your plugins and themes when you are coding or debugging. To get it done it uses XHProf, a PHP profiler made by the Facebook Dev Team (you must install it before activating the plugin).
<h4>Usage</h4>
By default the profiling is disabled, activate <code>WP_DEBUG</code> on your <code>wp-config.php</code> to enable it. After doing it, all your wordpress pages will have a link at bottom with the profiling data.
<h4>¿What is XHProf?</h4>
From <a href="" title="From PHP documentation" rel="nofollow ugc">http://www.php.net/manual/en/intro.xhprof.php</a>
XHProf is a light-weight hierarchical and instrumentation based profiler. During the data collection phase, it keeps track of call counts and inclusive metrics for arcs in the dynamic callgraph of a program. It computes exclusive metrics in the reporting/post processing phase, such as wall (elapsed) time, CPU time and memory usage. A functions profile can be broken down by callers or callees. XHProf handles recursive functions by detecting cycles in the callgraph at data collection time itself and avoiding the cycles by giving unique depth qualified names for the recursive invocations.
XHProf includes a simple HTML based user interface (written in PHP). The browser based UI for viewing profiler results makes it easy to view results or to share results with peers. A callgraph image view is also supported.
XHProf reports can often be helpful in understanding the structure of the code being executed. The hierarchical nature of the reports can be used to determine, for example, what chain of calls led to a particular function getting called.
XHProf supports ability to compare two runs (a.k.a. “diff” reports) or aggregate data from multiple runs. Diff and aggregate reports, much like single run reports, offer “flat” as well as “hierarchical” views of the profile.
Additional documentation can be found via the xhprof website » [http://pecl.php.net/package/xhprof]
<h4>Support</h4>
Comments, questions, feature requests and bug reports are welcome: <a href="http://www.berriart.com/en/xhprof-profiler/" title="XHProf Profiler" rel="nofollow ugc">http://www.berriart.com/en/xhprof-profiler/</a>

WP XHProf Profiler

Adds PHP profiling support to your Wordpress using Facebook's XHProf Profiler.

F12 Profiler vs WP XHProf Profiler