Synthetic Monitoring
What Synthetic Monitoring Is
Synthetic monitoring runs scripted checks against your site and APIs on a fixed schedule from external locations, instead of waiting for real traffic to reveal a problem. Because the checks run whether or not anyone is using your product, they catch an outage at 3am on a low-traffic endpoint just as reliably as one at peak. In LoadFocus, a synthetic check is an API check, a multistep API check, or a browser check, running from your chosen cloud regions.
Synthetic Monitoring vs Real-User Data
The two answer different questions, and LoadFocus provides both.
| Synthetic monitoring | Real-user field data | |
|---|---|---|
| Where the data comes from | Your own scripted checks | Aggregated from real Chrome users over the trailing 28 days |
| Schedule | Runs on a fixed interval you choose | Reflects whatever traffic actually occurred |
| Works with no traffic | Yes | No |
| Answers | "Is it broken, and where?" | "What are visitors actually experiencing?" |
| In LoadFocus | This page | Real-User Field Data (CrUX) |
Synthetic tells you something is down and which step failed. Real-user field data tells you what the people on your site experienced. Google uses field data for the Core Web Vitals assessment, so it is the one that affects your assessment, while synthetic is the one that pages you at night.
The Three Check Types
Which one you need depends on how much of the journey has to work.
API checks send a single HTTP request and assert on the response. Use them for one endpoint, a health route, or a third-party dependency.
Multistep API checks run an ordered sequence of HTTP requests as a single check, passing data from earlier responses into later requests. Use them when one request cannot prove the API works end to end, for example log in, capture the token, then call a protected endpoint with it.
Browser checks run a real Playwright script in a headless Chromium browser and drive your site the way a visitor would. Use them for full journeys, login, search, checkout, or any flow that spans several pages.
What You Get When a Check Fails
Browser checks capture a full set of artifacts on every run:
- Screenshots of the pages the script visited.
- Console logs from the browser.
- Network logs for every request the page made.
- A trace you can open to replay the run step by step.
- Per-step timings, so you can see which step slows a flow down.
- Video on failure, which can be enabled to watch what went wrong.
A browser check can also carry a degraded threshold on total duration in milliseconds. A run that passes but exceeds it is reported as degraded rather than healthy, and alerts on the duration metric are supported, so you hear about a flow getting slow before it breaks outright.
Scheduling and Locations
Checks run from 26 cloud regions across North and South America, Europe, Asia Pacific, Africa and the Middle East, so you can measure a journey from where your users actually are.
How many checks and locations you get depends on your plan. On the free plan you can run up to 10 checks with up to 6 locations per check and 10,000 check runs per month, with one day of data retention. Browser checks are not included on the free plan and are available on paid plans, where they have their own monthly browser-run quota separate from API check runs. See the pricing page for current limits.
For the shared settings, frequency, locations, alert channels, activate and mute, see How to Create a New API Check.
FAQ
What is synthetic monitoring?
Synthetic monitoring runs scripted checks against your site and APIs on a schedule from external locations, rather than waiting for real traffic to surface a problem. It tells you an endpoint or a user journey is broken before a customer finds it.
What is the difference between synthetic monitoring and real user monitoring?
Synthetic monitoring runs your own scripted checks on a fixed schedule, so you get consistent data even when traffic is low or zero. Real-user data reports what actual visitors experienced. Synthetic tells you something is down; real-user data tells you how many people it affected.
Which synthetic monitoring checks does LoadFocus include?
API checks for single endpoints, multistep API checks for chained request flows, and browser checks that drive a real browser through a full user journey with Playwright. All three run from the same cloud regions and share the same alert channels.
Which browser do synthetic browser checks use?
Browser checks run a Playwright script in headless Chromium from LoadFocus cloud regions, so the flow is exercised the way a visitor would experience it rather than as a plain HTTP request.
How many locations can synthetic checks run from?
Checks run from 26 cloud regions. How many you can select for a single check depends on your plan; the free plan allows 6 locations per check.
Is synthetic monitoring included on the free plan?
API checks and multistep API checks are. The free plan covers 10 checks, 6 locations per check and 10,000 check runs per month. Browser checks are a paid feature.