What is the difference between synthetic monitoring and real user monitoring?

Synthetic monitoring runs scripted checks on a schedule from outside your infrastructure, so it can detect outages with no traffic and trigger alerts. Real user monitoring (RUM) only measures real visitor sessions, which makes it ideal for field performance data but unable to detect a full outage, since a down site has no visitors to report. Most teams run both together.

How often should synthetic checks run?

For uptime monitoring, a 1-minute interval is common because it caps detection time at roughly one minute. Less critical endpoints are often checked every 5 minutes to reduce noise and load. The interval directly sets your worst-case detection delay.

Can synthetic monitoring catch problems other than a site being down?

Yes. Beyond a page failing to load, scripted checks can flag slow responses that breach a latency threshold, broken transaction flows such as a failing checkout, expiring TLS certificates, DNS resolution failures, and incorrect page content, all before real users are affected.

Where are synthetic checks run from?

They run from external monitoring locations spread across regions, never from inside your own infrastructure, so they see the site the way a real visitor on the public internet does. Running the same check from several locations also stops a single regional network blip from being mistaken for a real outage, since a failure has to reproduce from multiple vantage points before it triggers an alert.

What Is Synthetic Monitoring?

Reviewed by Ionut Caval · Updated June 2026

Synthetic monitoring runs automated, scripted checks against a website or API from outside your infrastructure on a fixed schedule. Because it generates its own traffic rather than waiting on real visitors, it catches outages and regressions even when nobody is on the site.

Synthetic monitoring is the proactive, alerting layer of reliability. A monitoring service runs the same request a visitor would (loading a page, calling an API, or stepping through a scripted flow like login or checkout) from external locations every few minutes, then checks the response code, content, and timing against what you expect. Because the traffic is generated on a schedule rather than by visitors, it answers one question continuously: is the site up and working right now?

How it works

Each check is a small automated script run from one or more external regions. A simple uptime check confirms the page returns HTTP 200 within a timeout; a transaction check can submit a form and assert that the next page contains an expected element. The interval sets how fast you find out about a problem: at a 1-minute frequency you learn of an outage within about a minute, while a 5-minute interval can leave a failure undetected for up to five. Common forms include:

Uptime checks: confirm a URL responds correctly from outside your network
API checks: validate status codes, response bodies, and latency on endpoints
Transaction checks: replay multi-step flows such as sign-in or checkout
Certificate and DNS checks: catch expiring TLS certificates or resolution failures

Synthetic vs. real user monitoring

Synthetic monitoring's counterpart is real user monitoring (RUM), which measures actual visitor sessions. The two are complementary rather than competing: synthetic detects outages and regressions before customers notice, even at 3 a.m. with zero traffic, while RUM describes real-world performance across the devices and networks people genuinely use. Crucially, RUM cannot detect a full outage because a down site has no visitors to send data, so synthetic checks remain the source of truth for availability and the trigger for alerts. For a side-by-side comparison, see synthetic monitoring vs. real user monitoring.

In practice, synthetic monitoring is what feeds your uptime metric and updates your public status page the moment a check fails. Pulsetic's uptime and API monitoring runs these checks from multiple regions so a single local network blip is not mistaken for a real outage.

Frequently asked questions

What is the difference between synthetic monitoring and real user monitoring?

Synthetic monitoring runs scripted checks on a schedule from outside your infrastructure, so it can detect outages with no traffic and trigger alerts. Real user monitoring (RUM) only measures real visitor sessions, which makes it ideal for field performance data but unable to detect a full outage, since a down site has no visitors to report. Most teams run both together.
How often should synthetic checks run?

For uptime monitoring, a 1-minute interval is common because it caps detection time at roughly one minute. Less critical endpoints are often checked every 5 minutes to reduce noise and load. The interval directly sets your worst-case detection delay.
Can synthetic monitoring catch problems other than a site being down?

Yes. Beyond a page failing to load, scripted checks can flag slow responses that breach a latency threshold, broken transaction flows such as a failing checkout, expiring TLS certificates, DNS resolution failures, and incorrect page content, all before real users are affected.
Where are synthetic checks run from?

They run from external monitoring locations spread across regions, never from inside your own infrastructure, so they see the site the way a real visitor on the public internet does. Running the same check from several locations also stops a single regional network blip from being mistaken for a real outage, since a failure has to reproduce from multiple vantage points before it triggers an alert.

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