Methods
Error Tracking
Capturing JavaScript errors and failed requests from real sessions, grouped so you see the real problems.
A page can score perfect vitals and still be broken for a segment of users because a script throws. Error tracking records those failures from the browser, with enough context (page, browser, sequence) to reproduce them.
Similar errors are collapsed into one fingerprint, so a thousand occurrences of the same bug show up as a single ranked issue instead of noise.
Related terms
- RUMReal User MonitoringMeasuring performance from the browsers of your actual visitors, on their real devices and networks.
- Synthetic MonitoringScheduled, repeatable tests that load a page in a controlled environment on a fixed interval.
- Lab data vs field dataLab data comes from a controlled test; field data comes from real visitors. Both matter, for different reasons.
- LighthouseGoogle's open-source tool that audits a page in a lab run and scores performance, accessibility, SEO and more.
- CrUXChrome UX ReportGoogle's public dataset of real-world Core Web Vitals, aggregated from opted-in Chrome users.
- p75Percentile (p75)The value below which a given share of visits fall. p75 means 75 percent were at least this fast.
- Web Vitals AttributionThe extra diagnostic data that explains why a metric was slow, not just how slow it was.
- Web AnalyticsTraffic and behaviour measurement: page views, visitors, referrers and journeys, alongside performance.
- AlertingNotification rules that tell you when a metric breaches a threshold or degrades, before customers complain.
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.
fastmon One
€99/month
1M pageviews included.
More volume, longer retention or a contract of your own? Enterprise on request. See all plans