WordPress.org

This plugin captures real user metrics about what elements are displayed on the page across a variety of device form factors (e.g. desktop, tablet, and phone) in order to apply loading optimizations which are not possible with WordPress’s current server-side heuristics.
This plugin is a framework dependency which does not provide optimization functionality on its own. For that, please install the <a href="https://wordpress.org/plugins/image-prioritizer/" rel="ugc">Image Prioritizer</a> and <a href="https://wordpress.org/plugins/embed-optimizer/" rel="ugc">Embed Optimizer</a> dependent plugins (among <a href="https://github.com/WordPress/performance/labels/%5BPlugin%5D%20Optimization%20Detective" rel="nofollow ugc">others</a> to come from the WordPress Core Performance team). There are currently no settings and no user interface for this plugin since it is designed to work without any configuration.
Your site must currently have the REST API accessible to unauthenticated frontend visitors since this is how real user metrics are collected about pages on your site; nevertheless, <a href="https://github.com/WordPress/performance/issues/1311" rel="nofollow ugc">exploration</a> is underway for providing alternative mechanisms for collecting the metrics. Also, please note that no metrics are currently collected from Safari since it does not yet support the <a href="https://developer.mozilla.org/en-US/docs/Web/API/LargestContentfulPaint" rel="nofollow ugc">Largest Contentful Paint</a> metric, but support for this <a href="https://web.dev/explore/learn-core-web-vitals" rel="nofollow ugc">Core Web Vitals</a> metric is coming this year <a href="https://webkit.org/blog/16458/announcing-interop-2025/#core-web-vitals" rel="nofollow ugc">via Interop 2025</a>.
Please refer to the <a href="https://github.com/WordPress/performance/blob/trunk/plugins/optimization-detective/docs/README.md" rel="nofollow ugc">full plugin documentation</a> for a <a href="https://github.com/WordPress/performance/blob/trunk/plugins/optimization-detective/docs/introduction.md" rel="nofollow ugc">technical introduction</a>, <a href="https://github.com/WordPress/performance/blob/trunk/plugins/optimization-detective/docs/hooks.md" rel="nofollow ugc">filter/action hooks</a>, and <a href="https://github.com/WordPress/performance/blob/trunk/plugins/optimization-detective/docs/extensions.md" rel="nofollow ugc">extensions</a> that show use cases and examples. You can also watch the talk from WordCamp Asia 2025: <a href="https://weston.ruter.net/2025/02/21/boosting-performance-with-optimization-detective/" rel="nofollow ugc">Boosting Performance with Optimization Detective</a>.

Optimization Detective

Provides a framework for leveraging real user metrics to detect optimizations for improving page performance.

MUDRAVA

MUDRAVA RUM captures real user performance data from your WordPress site visitors. Unlike synthetic testing tools, this plugin measures actual user experience including Time to First Byte (TTFB), Largest Contentful Paint (LCP), server generation time, total page load time, and more.
Features:
<ul>
<li>Collects TTFB, LCP, server generation time, total load, memory peak, device type, network type, country, and session ID</li>
<li>Live Monitor dashboard with real-time log viewing</li>
<li>Filterable by session ID, URL, device type, and network type</li>
<li>On-demand performance reports with averages and P75 LCP</li>
<li>Scheduled email summaries (daily or weekly via WP-Cron)</li>
<li>Critical TTFB alerts with configurable thresholds</li>
<li>Configurable sampling rate and URL blacklist</li>
<li>Role-based exclusion (skip tracking for specific user roles)</li>
<li>Automatic data retention management (max records and days)</li>
<li>Color-coded performance indicators (good/warning/poor)</li>
</ul>
How It Works:
A lightweight JavaScript collector runs on your site’s frontend, gathering Core Web Vitals and performance metrics from each page view. Data is sent via the WordPress REST API and stored in a custom database table. The admin dashboard provides a Live Monitor view, filterable reports, and email summaries.
Links:
<ul>
<li><a href="https://mudrava.com/en/projects/mudrava-rum-wordpress-plugin/" rel="nofollow ugc">Plugin page</a></li>
<li><a href="https://github.com/Mudrava/Mudrava-RUM" rel="nofollow ugc">GitHub repository</a></li>
</ul>
<h3>Privacy</h3>
Data Collection:
This plugin collects anonymized performance metrics (TTFB, LCP, load times, device type, network type) from site visitors. No personally identifiable information (PII) is collected or stored. Session IDs are randomly generated and not linked to user accounts.
External Requests:
This plugin does not send data to external third-party services. All collected data is stored locally in your WordPress database.
Cookies:
This plugin does not use cookies. Session IDs are stored in the browser’s sessionStorage.
Data Retention:
Collected data is automatically purged based on your configured retention settings (maximum records and retention days).

MUDRAVA RUM

Real User Monitoring (RUM) plugin for WordPress that tracks TTFB, LCP, server generation time, and other performance metrics from real visitors.

Optimization Detective vs MUDRAVA RUM