What is the difference between Real User Monitoring (RUM) and synthetic monitoring?

RUM passively measures page load times and Core Web Vitals from real visitors, while synthetic monitoring actively runs scheduled browser tests 24/7.

Real User Monitoring (RUM) and Synthetic Monitoring complement each other:

  • Real User Monitoring (RUM): Uses a lightweight script in your site head to measure actual visitor performance—including page load time, Time to First Byte (TTFB), Largest Contentful Paint (LCP), and AJAX timings—broken down by country, browser, and device.
  • Synthetic Monitoring: Runs scheduled, automated browser tests from controlled global locations even when no visitors are on your site, catching functional breakages before customers encounter them.

In Acumen Logs, RUM does not draw from your uptime, SSL, or WHOIS check allowances.

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