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.

Pierre Lannoy

Hosterra

Truthful user experience and browsing performances monitoring.
Vibes is a robust user experience and browsing performances monitoring solution that analyzes perceived performances from users’ viewpoint.
It is fully autonomous – does not rely on external services and does not require any API keys, works on any type of hosting and in any type of environment – including staging, intranets or password protected sites.
By continuously monitoring user experience, Vibes can report:
<ul>
<li>navigation performance KPIs per pages – like latency, redirections, browser caching hit rates, etc.;</li>
<li>network timelines as if you were in the dev tools of your users’ browsers;</li>
<li>resources details – like initiators, protocols, mime types, average sizes, etc.;</li>
<li>Web Vitals: LCP, FID, CLS, FCP and TTFB.</li>
</ul>
It can segment all this data per:
<ul>
<li>user type (anonymous vs. authenticated);</li>
<li>channel (frontend vs. backend);</li>
<li>country (requires the free <a href="https://wordpress.org/plugins/ip-locator/" rel="ugc">IP Locator</a> plugin);</li>
<li>device classes and types (requires the free <a href="https://wordpress.org/plugins/device-detector/" rel="ugc">Device Detector</a> plugin).</li>
</ul>
Vibes supports multisite report delegation (see FAQ).
Vibes supports WP-CLI commands to:
<ul>
<li>display (past or current) performances signals in console – see <code>wp help vibes tail</code> for details;</li>
<li>toggle on/off main settings – see <code>wp help vibes settings</code> for details.</li>
</ul>
For a full help on WP-CLI commands in Vibes, please <a href="https://perfops.one/vibes-wpcli" rel="nofollow ugc">read this guide</a>.
<blockquote>
Vibes is part of <a href="https://perfops.one/" rel="nofollow ugc">PerfOps One</a>, a suite of free and open source WordPress plugins dedicated to observability and operations performance.
</blockquote>
Vibes is a free and open source plugin for WordPress. It integrates many other free and open source works (as-is or modified). Please, see ‘about’ tab in the plugin settings to see the details.
<h4>Support</h4>
This plugin is free and provided without warranty of any kind. Use it at your own risk, I’m not responsible for any improper use of this plugin, nor for any damage it might cause to your site. Always backup all your data before installing a new plugin.
Anyway, I’ll be glad to help you if you encounter issues when using this plugin. Please read carefully the FAQ at the bottom of this page before requesting support.
<h4>Donation</h4>
If you like this plugin or find it useful and want to thank me for the work done, please consider making a donation to <a href="https://www.laquadrature.net/en" rel="nofollow ugc">La Quadrature Du Net</a> or the <a href="https://www.eff.org/" rel="nofollow ugc">Electronic Frontier Foundation</a> which are advocacy groups defending the rights and freedoms of citizens on the Internet. By supporting them, you help the daily actions they perform to defend our fundamental freedoms!

Vibes

Great plugin

Truthful user experience and browsing performances monitoring.

Optimization Detective vs Vibes