Welcome to fastmon

Real User Monitoring from the EU. For teams that want to know what their customers actually experience.

Fastmon measures how your site actually feels for real visitors: Core Web Vitals, errors, and performance, straight from the browser. Out of that come dashboards your team can use.

Get started

Get fastmon running on a site in under five minutes.

Implement fastmon

One script tag in your <head>. Works on any site: static HTML, Next.js, WordPress, Shopware, or a tag manager. Five minutes.

Verify the implementation

Check that data is coming in, and what to do when it isn't.

Understand fastmon

You're new to RUM or to fastmon and want to get your bearings before you set anything up.

Concepts

Organizations, sites, sessions, releases: the small set of resources that make up the product.

Privacy: what we don't collect

No cookies, no IPs stored, no fingerprinting.

Tracker settings

Presets (Minimal, Standard, Full) and the per-setting configuration: what the tracker collects.

Look up a metric

You're staring at a Web Vitals number and want to know what it means, or how to make it go away.

Web Vitals overview

LCP, INP, CLS, FCP, TTFB: definitions, thresholds, and where to start.

LCP

The page-load metric.

INP

The runtime-responsiveness metric.

Experience Score

A single 0–10 number combining LCP, INP, CLS, FCP, TTFB, page-load time, and error rate.

Explore your data

Setup is done and you want to see what the tracker is collecting.

Analytics

Traffic, sessions, errors, and per-segment Experience Scores.

Synthetic Monitoring

Scheduled Lighthouse and TTFB lab tests, side by side with your RUM data. Beta.

Get the most out of fastmon

You want to connect fastmon to your CI/CD, use alerting, or feed your existing dashboards.

Compare releases

Tag deploys from CI/CD and answer 'did this deploy regress LCP?' in one query.

Notification rules

Alert when a metric crosses a threshold or worsens against the previous window.

API reference

Authentication, errors, pagination, and all resource endpoints.

Fastmon in brief

See how your site really performs for real visitors. Fastmon shows you how your pages behave for actual users in the field, not just in the lab.
Privacy-first, no asterisks. No third-party cookies, no IPs on disk, no cross-site tracking. EU infrastructure end-to-end. Details on Privacy.
Scales without you noticing. Beacons go into a columnar analytics store via batched inserts. Built to handle real production traffic without you having to tune anything.
Standard Web Vitals, no homegrown numbers. LCP, INP, CLS, FCP, TTFB plus navigation, resource, and long-task timing, all through the same browser APIs as Chrome's web-vitals library. Comparable with anything else you read about CWV.