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.

Site24x7

Real User Monitoring by Site24x7 gives accurate insight into real users application experience and helps visualise web app interaction patterns. Real User Monitoring provides deep insight into key performance metrics right from the initiation of the URL until the request is served back to the browser.
The RUM plugin helps you add your Site24x7 RUM code snippet to the Head tag of your WordPress blog. Once added, Site24x7 immediately starts collecting data from your WordPress blog’s visitors. You can view all that collected data in <a href="https://www.site24x7.com/app/apm#/apm/rum/list/" rel="nofollow ugc">Site24x7 console</a>.
Site24x7 Real User Monitoring provides better understanding of performance issues by providing actionable data like showing real user performance by region, browser type, device used to access the application and more, these metric assist in pinpointing issues faster to make applications more fluid and user friendly. The back-end response time provides metrics from a server perspective calculating the time taken by the server to serve the request and statistics such as the page rendering time, document processing time and document downloading time, all of which help developers tailor applications to be more fluid to end users.please refer the help document for more information <a href="https://www.site24x7.com/help/apm/rum.html" rel="nofollow ugc">site24x7-rum</a>.
P.S: You will need a Site24x7 account for this plugin. If you don’t have one, grab one at <a href="https://www.site24x7.com/signup.html?pack=4&l=en" rel="nofollow ugc">site24x7.com</a> – its super-easy!

Site24x7 Real User Monitoring

Real User Monitoring (RUM) by Site24x7 provides deep and accurate insight into real users’experience on your WordPress setup.

Optimization Detective vs Site24x7 Real User Monitoring