What Is a Synthetic Monitor? Scripted Checks Explained
A synthetic monitor runs scripted, simulated user interactions against a service on a schedule, proactively checking that key flows work even when no real user is exercising them.
Synthetic monitoring goes beyond asking "is the service up" to asking "does the service actually work." It runs predefined journeys, log in, search, add to cart, on a timer, so problems are caught by the monitor before customers hit them. It is the proactive counterpart to passively watching real traffic.
Simulated user journeys
A synthetic monitor scripts a sequence of steps that represent something a user does, such as completing a checkout, and replays it regularly. By exercising the full path, not just one endpoint, it verifies that an entire critical flow functions end to end, not merely that the homepage loads.
Proactive, not reactive
Because synthetic checks run continuously regardless of real traffic, they catch breakages during quiet periods and before users notice. This proactivity is the main advantage over real-user monitoring, which can only observe problems after a real person has already experienced them.
Consistent and comparable
Synthetic monitors run the same scripted steps every time from controlled locations, so their results are consistent and trendable. That makes them good for tracking performance over time and for comparing behavior across regions, free of the variability of real user conditions.
Synthetic monitoring in CI/CD
Synthetic checks make excellent post-deploy validation. After a release, running the critical user journeys against the live service confirms that real flows still work before the deploy is considered successful. A failed synthetic flow right after deploy is a clear trigger to roll back.
Synthetic vs real-user monitoring
Synthetic monitoring is controlled and proactive but only tests the journeys you scripted, from where you run them. Real-user monitoring observes actual users across all paths and conditions, but only reactively. The two are complementary: synthetics catch known critical flows early, RUM reveals the unexpected.
Key takeaways
- A synthetic monitor replays scripted user journeys on a schedule.
- It is proactive, catching breakage before real users do.
- Consistent scripts make results trendable and comparable.
- It is well suited to post-deploy validation of critical flows.