Building blocks
Cache-Status
Whether a response came from a CDN edge, the origin server or the browser cache.
The same URL can be fast or slow depending on where it was served from. Recording cache status per request shows your real hit rate and surfaces resources that keep missing the cache and hitting the origin.
It turns caching from a hopeful configuration into something you can actually verify against real traffic.
Related terms
- BeaconThe small data packet the tracker sends to fastmon with a visit's measurements.
- TrackerThe lightweight script you embed once; it measures Core Web Vitals and errors directly in the browser.
- Stitchfastmon's short-lived, edge-derived identifier that groups a visit without cookies or cross-site tracking.
- SessionOne continuous visit: the sequence of page views and interactions a visitor makes before going idle.
- PageviewA single page load or, in a single-page app, a route change counted as its own view.
- Collection modesPresets (Light, Standard, Full) that decide how much detail the tracker collects.
- Server-TimingAn HTTP header your backend can send to break down where server time was spent, visible in RUM.
Monitoring that
belongs in the EU.
Read-only by default: no cookies*, no long-lived identifiers, no US provider in the data path. Live in about five minutes.
Light
€29/month
200,000 pageviews included.
Need debugging and all features? Standard from €99 for 1M pageviews. Enterprise on request. See all plans