Here’s an uncomfortable scenario: a customer tweets that your checkout is broken. Your support team starts getting tickets. Your engineers scramble to investigate. Meanwhile, your internal dashboards show everything green.
The problem was real. Your monitoring just couldn’t see it.
This is the gap that synthetic monitoring fills. Instead of waiting for real users to encounter problems - and hoping your monitoring catches them - synthetic monitoring actively tests your systems the way users would, finding issues before customers become your alerting system.
What Is Synthetic Monitoring?
Synthetic monitoring, also called active monitoring or proactive monitoring, uses automated scripts to simulate user interactions with your website, application, or API. These scripts run continuously from multiple locations around the world, checking that everything works as expected.
Think of it as a robot user that visits your site every few minutes, clicks buttons, fills out forms, and reports back whether things worked.
Unlike Real User Monitoring (RUM), which passively collects data from actual users as they interact with your site, synthetic monitoring proactively generates traffic to test your systems - even when no real users are online.
Synthetic vs. Real User Monitoring
Both approaches have strengths. Understanding the difference helps you use each effectively.
| Aspect | Synthetic Monitoring | Real User Monitoring |
|---|---|---|
| Approach | Active - simulates user requests | Passive - observes actual users |
| Data source | Scripted tests from controlled locations | Real browser sessions from actual users |
| Traffic required | None - works without real users | Yes - needs actual user traffic |
| Coverage | Limited to defined test scenarios | Captures all user interactions |
| Consistency | Highly consistent, repeatable tests | Variable based on user behavior/devices |
| Best for | Availability, regression testing, pre-production | Long-term trends, real-world performance |
Based on comparison research from DebugBear and MDN
What Synthetic Monitoring Catches
Synthetic monitoring excels at:
- Availability issues - Is the site up?
- Regression detection - Did the latest deploy break something?
- Pre-production testing - Does it work before users see it?
- Third-party monitoring - Are payment processors, CDNs, and APIs working?
- Geographic issues - Is performance different in different regions?
What Real User Monitoring Catches
RUM excels at:
- Real-world device diversity - How does it perform on that specific Android phone?
- Network variability - What about users on slow connections?
- Unexpected user paths - What if users do something you didn’t script?
- Business correlation - How does performance affect conversion?
The Answer: Use Both
The best practice is to combine both: synthetic monitoring for proactive reliability, RUM for real-world truth and business impact.
Only choosing one monitoring type will not result in an ideal strategy. A comprehensive monitoring solution should include both to get a 360-degree view of your application.
Why Synthetic Monitoring Matters
Find Problems Before Users Do
This is the core value proposition. Modern applications are expected to be available 24/7, and synthetic monitoring enables teams to identify problems before they affect actual end users.
When users detect problems first, it damages trust and impacts business. Synthetic monitoring flips this equation - by simulating user interactions, it detects anomalies before they impact real users.
Monitor Without Traffic
RUM has a chicken-and-egg problem: it requires traffic to be useful. In pre-production environments, you have no real users. During off-peak hours, traffic may be too low to catch issues quickly.
Synthetic monitoring offers a proactive approach by simulating user behavior in controlled, repeatable environments. You can test specific user flows, geographic conditions, and network environments on demand - even when no users are actively using the system.
Test Third-Party Dependencies
Your site depends on services you don’t control: payment processors, CDNs, authentication providers, analytics platforms. When they have problems, your users experience problems.
Synthetic monitoring gives you the opportunity to monitor the performance of third-party plugins, services, and APIs - especially critical for e-commerce applications where a payment processor outage means lost revenue.
Faster Detection, Faster Resolution
Detection speed directly impacts resolution time. MTTR only starts once a problem is detected. If a database outage goes undetected for two hours but only takes 15 minutes to fix, the impact is still over two hours of customer pain.
Synthetic monitoring with frequent checks can catch issues in seconds compared to minutes with traditional tools. That difference translates directly to reduced customer impact.
Types of Synthetic Monitoring Checks
Not all synthetic checks are the same. Different check types serve different purposes.
HTTP/HTTPS Checks (Uptime Monitoring)
The most basic form of synthetic monitoring. An automated request hits your URL and checks:
- Did the server respond?
- Was the response code acceptable (usually 200)?
- Did the response contain expected content?
- How long did it take?
HTTP monitoring sends requests to your URL and evaluates response status codes, response times, and content to confirm resource availability.
Best for: Basic availability monitoring, API endpoint health
SSL/TLS Certificate Monitoring
SSL/TLS monitoring tracks certificate validity, expiration, and encryption strength. An expired certificate means browsers show scary warnings and users can’t access your site securely.
Best for: Preventing certificate expiration surprises
DNS Monitoring
DNS monitoring checks domain name resolution speed and availability globally, ensuring records resolve accurately. DNS failures make your entire site unreachable even when servers are healthy.
Best for: Catching DNS configuration errors, monitoring DNS propagation
API Monitoring
Beyond simple HTTP checks, API monitoring validates:
- Response structure and content
- Authentication flows
- Status codes and headers
- Response times with millisecond accuracy
You can monitor REST, GraphQL, and SOAP endpoints with detailed validation.
Best for: Backend services, microservices, integrations
Transaction Monitoring (Browser Checks)
The most sophisticated form of synthetic monitoring. Transaction monitoring uses scripts that can log in to a service, complete forms, purchase products, and respond to system prompts.
This tests the “happy paths” - the critical user journeys that must work for your business to function.
Best for: Checkout flows, login sequences, multi-step processes
Critical User Journeys to Monitor
Before implementing synthetic monitoring, identify the most critical user journeys - the flows that drive your business. These are where synthetic monitoring delivers the most value.
E-commerce
| Journey | What to Monitor |
|---|---|
| Product search | Search returns results, filters work |
| Product pages | Images load, pricing displays correctly |
| Add to cart | Items can be added, cart updates |
| Checkout | Entire purchase flow completes |
| Payment processing | Payment gateway responds correctly |
Monitoring the checkout process ensures customers can complete purchases without friction. Synthetic monitoring automates the entire journey, identifying problems like broken buttons, validation errors, or payment gateway failures before they affect users.
SaaS Applications
| Journey | What to Monitor |
|---|---|
| Login | Authentication works, redirects correctly |
| Core features | Primary functionality responds |
| Data operations | CRUD operations complete |
| Integrations | Third-party connections function |
| Logout | Session terminates properly |
A B2B software provider found that their login process occasionally failed during their authentication service’s database backup window. The issue affected only 2% of login attempts but led to support tickets and customer frustration that basic monitoring didn’t detect.
Content Sites
| Journey | What to Monitor |
|---|---|
| Homepage | Loads completely, images appear |
| Navigation | Links work, menus function |
| Search | Returns relevant results |
| Content pages | Articles render, media plays |
| Subscription | Sign-up forms work |
The Power of Multiple Locations
One of synthetic monitoring’s key advantages is testing from multiple geographic locations.
Why Location Matters
A key aspect of synthetic monitoring is that tests run globally. If your application has a global presence, it’s not enough to know that things work correctly from wherever your office is. There might be issues related to one specific region.
Common location-specific issues include:
- CDN problems - A CDN edge server may be misconfigured in one region
- DNS issues - DNS propagation may be incomplete in some areas
- Routing problems - Network paths may have issues affecting specific regions
- Compliance blocks - Content may be inadvertently blocked in certain countries
Best Practices for Multi-Location Monitoring
Setting up monitors across geographically distributed data centers helps uncover location-specific latency or connectivity issues and ensures a consistent experience for global users.
Recommendations:
- Test from locations where you have significant user traffic
- Include at least one location per major region (Americas, Europe, Asia-Pacific)
- For critical paths, test from multiple locations within regions
- Compare performance across locations to identify outliers
Check Frequency: How Often to Test
Different check types warrant different frequencies.
| Check Type | Recommended Frequency | Rationale |
|---|---|---|
| HTTP/Uptime | Every 1-3 minutes | Catch outages quickly |
| API checks | Every 3-5 minutes | Balance thoroughness with load |
| Transaction checks | Every 5-15 minutes | Complex scripts need more time |
| SSL checks | Once daily | Certificates don’t change often |
| DNS checks | Once daily | Records are relatively stable |
Based on industry best practices
The tradeoff: more frequent checks catch issues faster but generate more load and may cost more. For critical paths during high-traffic periods, higher frequency is worth it.
A Growing Market
Synthetic monitoring isn’t a niche practice - it’s becoming standard.
The global synthetic monitoring market reached around USD 1.69 billion in 2025, driven by increasing demand for high-performance applications and seamless user experiences.
The market is expected to grow at 15.3% annually through 2035, reaching nearly $7 billion.
This growth reflects the reality that proactive monitoring has moved from nice-to-have to necessity as businesses become more dependent on digital services.
Common Synthetic Monitoring Mistakes
Testing Only the Homepage
Your homepage might be up while your checkout is broken. Synthetic monitoring tests are limited to the scenarios you define - if you only check the homepage, you’ll only know about homepage problems.
Fix: Monitor critical user journeys, not just entry points.
Testing Only From One Location
If you only test from US-East and your European CDN has problems, you won’t know until European customers complain.
Fix: Test from locations that represent your actual user base.
Alert Fatigue From Over-Testing
Testing every second from 50 locations generates noise. Too sensitive leads to alert fatigue; too lenient means missing critical issues.
Fix: Balance frequency with actionability. Not every check needs to run every minute.
Ignoring Synthetic Data
Setting up monitoring is pointless if no one acts on it. Synthetic monitoring allows organizations to spot performance issues and availability problems proactively - but only if teams respond to what they find.
Fix: Ensure alerts reach the right people and trigger clear response procedures.
Getting Started With Synthetic Monitoring
Step 1: Identify Critical Paths
List the user journeys that matter most to your business:
- What paths generate revenue?
- What functions would cause support tickets if broken?
- What would damage your reputation if unavailable?
Step 2: Start Simple
Begin with basic HTTP checks on your most critical endpoints. You don’t need sophisticated browser scripts on day one.
Step 3: Add Geographic Coverage
Once basic checks are running, add locations that represent your user base.
Step 4: Add Transaction Monitoring
For critical multi-step flows (login, checkout, signup), add browser-based transaction monitoring.
Step 5: Tune and Iterate
Monitor alert volume. If you’re getting too many false positives, adjust thresholds. If you’re missing issues, increase check frequency or add coverage.
The Goal: Know Before They Do
The ultimate measure of synthetic monitoring success is simple: do you find problems before your customers do?
When your monitoring tells you about issues first, you can:
- Fix problems before users notice
- Communicate proactively if there’s customer impact
- Protect your reputation by demonstrating competence
- Reduce support ticket volume from confused users
When customers find problems first, you’re reactive - scrambling to catch up while trust erodes.
By running 24/7, synthetic monitoring can catch regressions, broken dependencies, or performance degradations before they affect customers. That’s the difference between monitoring as a formality and monitoring that actually protects your business.
Your customers shouldn’t be your monitoring system. Synthetic monitoring ensures they don’t have to be.
FlareWarden uses synthetic monitoring to check your websites, APIs, and services from multiple global locations. We simulate real user access to detect issues before your customers notice - so you can fix problems while they’re still invisible.