Wp Core Tools

<p>Speedix profiles PHP execution on your WordPress site, showing exactly which hooks and plugins are slow. Unlike page speed tests that just show load time, Speedix shows you <em>why</em> your site is slow.</p>
<p>Built for developers, agencies, and site administrators who need to diagnose performance issues at the code level.</p>
<h4>What It Does</h4>
<p>Measures every WordPress hook with microsecond precision and traces slow callbacks back to their source plugins using PHP Reflection. You get a clear breakdown of where time is spent: Core vs Theme vs Plugins.</p>
<p>The dashboard shows a health score (0-100), highlights the slowest hooks, and tracks performance trends over time. WooCommerce sites get a dedicated tab with categories for Checkout, Cart, Products, Orders, and more.</p>
<h4>Safe for Production</h4>
<ul>
<li>Sample rate control (10-100% of requests)</li>
<li>Threshold filtering to only log slow hooks</li>
<li>Overload protection auto-pauses if overhead spikes</li>
<li>Auto-cleanup from 1 hour to 7 days retention</li>
</ul>
<p>Quick presets let you switch between Safe Mode (10% sampling), Balanced, or Detailed profiling with one click.</p>
<h4>WooCommerce Support</h4>
<p>Works with HPOS (Custom Order Tables) and Cart/Checkout Blocks. Tracks checkout complexity: payment gateways, shipping methods, coupons, and session size.</p>
<h4>Export Options</h4>
<p>CSV, JSON, and Markdown exports for reporting and analysis.</p>
<h4>Why Not a Page Speed Test?</h4>
<p>GTmetrix and PageSpeed measure frontend delivery. Speedix measures server-side PHP execution. They answer different questions. Use both.</p>
<h4>Privacy</h4>
<p>All data stays in your WordPress database. No external API calls, no tracking, no telemetry. GDPR compliant by design.</p>
<h4>100% Free</h4>
<p>Every feature is included. No pro version, no upsells.</p>


Speedix

Pinpoint exactly which plugins and hooks slow your site. Real-time PHP profiling with visual dashboard, health scores, and zero guesswork.

Forge12 Interactive GmbH

<p>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.</p>
<h4>Features</h4>
<p><strong>Analysis & Diagnostics</strong></p>
<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>
<p><strong>Optimization Tools</strong></p>
<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 <strong>(Pro)</strong></li>
<li>CSS/JS Asset Manager – disable, defer, async per page or globally <strong>(Pro)</strong></li>
<li>Conditional Loading – shortcode, block, regex, archive, login status, post type, plugin <strong>(Pro)</strong></li>
<li>Smart auto-suggestions with source-based plugin detection after full scan <strong>(Pro)</strong></li>
<li>Asset Preload Manager – Link headers for critical assets <strong>(Pro)</strong></li>
<li>Critical CSS Generator & Applier – above-the-fold CSS per template <strong>(Pro)</strong></li>
<li>Unused CSS Removal – per page template, safelist, regex safelist <strong>(Pro)</strong></li>
<li>WebP Image Conversion with batch queue and backup <strong>(Pro)</strong></li>
<li>LQIP Image Placeholders – 20px blur-up previews with IntersectionObserver <strong>(Pro)</strong></li>
<li>Preload Key Requests – LCP images, fonts, critical resources <strong>(Pro)</strong></li>
<li>Script Delay – delays third-party JS until first user interaction <strong>(Pro)</strong></li>
<li>Local Google Fonts – GDPR-compliant WOFF2 self-hosting <strong>(Pro)</strong></li>
<li>YouTube/Vimeo Facade – thumbnail + play button instead of iframe <strong>(Pro)</strong></li>
<li>Database Cleanup – one-click per category or bulk action <strong>(Pro)</strong></li>
<li>Redis Object Cache Management – drop-in installation/removal <strong>(Pro)</strong></li>
<li>Scheduled Crawls & Cleanups via WP-Cron <strong>(Pro)</strong></li>
<li>Performance Budgets with email/webhook notifications <strong>(Pro)</strong></li>
<li>Settings Import/Export as JSON <strong>(Pro)</strong></li>
<li>One-Click Optimizer – automated optimization with backup & restore <strong>(Pro)</strong></li>
<li>License Management with activation/deactivation <strong>(Pro)</strong></li>
</ul>
<p><strong>User Interface</strong></p>
<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>
<p><a href="https://www.forge12.com/f12-profiler-pro/" rel="nofollow ugc">Get F12 Profiler Pro</a></p>
<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.

Speedix vs F12 Profiler