What Is Synthetic Monitoring? Simple Explanation for Developers

Synthetic monitoring uses simulated requests to test your website, API, or application's availability and performance. Instead of waiting for real users to encounter problems, synthetic monitoring proactively checks your services from multiple locations on a schedule—every 30 seconds to 5 minutes.

Think of it as automated QA that runs 24/7.

How Synthetic Monitoring Works

Synthetic Monitoring Process:
────────────────────────────────────────────────────
                        ┌─── US East Server
                        │    "Send GET /api/users"
Monitoring Schedule ────┼─── EU Server
(every 30 seconds)      │    "Send GET /api/users"
                        └─── Asia Server
                             "Send GET /api/users"

                              ↓

                        Collect Results:
                        • Status code: 200 OK
                        • Response time: 145ms
                        • Content valid: Yes

                              ↓

                        If failure → Alert
                        If slow → Alert
                        If success → Log & continue

The monitoring system:

1. Sends requests from multiple geographic locations
2. Validates responses against expected criteria
3. Measures response time
4. Alerts when something is wrong
5. Records data for historical analysis

Types of Synthetic Monitoring

1. Availability Monitoring (Uptime Checks)

Simple checks that verify services respond:

• HTTP/HTTPS requests
• TCP port checks
• DNS resolution
• Ping (ICMP)

Example: Check if https://api.example.com/health returns 200 OK

2. API Monitoring

More sophisticated API testing:

• Multiple endpoint checks
• Response validation
• Header verification
• JSON schema validation

Example: Verify /api/users returns valid JSON with expected fields

3. Browser/Transaction Monitoring

Scripted user journeys using headless browsers:

• Login flows
• Checkout processes
• Multi-step forms
• Visual regression

Example: Script that logs in, adds item to cart, and completes checkout

Synthetic vs Real User Monitoring (RUM)

When to Use Each

Use Synthetic Monitoring:

• Proactive availability checking
• Consistent baseline performance data
• Testing from multiple regions
• Off-hours monitoring (when no users online)
• Pre-production testing

Use Real User Monitoring:

• Understanding actual user experience
• Discovering unexpected usage patterns
• Geographic performance variations
• Device/browser-specific issues
• Conversion funnel analysis

Many teams use both.

Benefits of Synthetic Monitoring

1. Proactive Issue Detection

Find problems before users do:

• 2 AM outage detected instantly
• No need to wait for complaints
• Faster mean time to detection

2. Consistent Baselines

Same test, same locations, same conditions:

• Track performance over time
• Detect gradual degradation
• Compare releases objectively

3. Geographic Coverage

Test from locations matching your users:

• Detect regional outages
• Measure latency from different continents
• Verify CDN performance

4. No Dependency on Traffic

Works even when:

• No users are online
• It's 3 AM in your timezone
• You're just launching (no traffic yet)

Common Mistakes

1. Only Testing the Homepage

Your homepage might work while critical paths fail:

• Test /api/health for APIs
• Test /login for authentication
• Test /checkout for e-commerce

2. Single-Location Testing

One location can't detect regional issues and produces false positives from local network problems.

Use at least 3 locations.

3. Ignoring Response Time

A 200 OK that takes 30 seconds is effectively down. Set thresholds:

Warning: > 2 seconds
Critical: > 5 seconds

4. Alert Fatigue

Too many alerts = ignored alerts. Configure:

• 2-3 consecutive failures before alerting
• Reasonable thresholds
• Proper escalation

5. Not Testing User Journeys

Simple uptime checks miss complex failures. If checkout requires login + cart + payment, a simple HTTP check might miss issues in that flow.

Synthetic Monitoring Tools Comparison

For most teams, uptime monitoring (simple synthetic checks) is sufficient. Browser testing is valuable for complex user flows.

When Wakestack Is a Good Fit

Wakestack provides synthetic monitoring (uptime checks) combined with server monitoring and status pages:

• HTTP/HTTPS checks from multiple regions
• TCP, DNS, Ping monitoring
• 30-second intervals for fast detection
• Response validation including content matching
• Server metrics to understand why failures occur
• Status pages to communicate with users

What Wakestack Covers

For browser testing, consider dedicated tools like Checkly or Playwright. For availability monitoring with server visibility, Wakestack fits well.

Start synthetic monitoring — 5 free monitors, no credit card.

Quick Setup

1. Sign up at wakestack.co.uk/signup
2. Add monitors for your critical endpoints:
   • Homepage
   • API health endpoint
   • Authentication
   • Key user paths
3. Configure multi-region checks
4. Set alert thresholds appropriate for each endpoint
5. Create status page to communicate with users

Key Takeaways

• Synthetic monitoring uses simulated requests to test services
• It catches issues before real users encounter them
• Uptime monitoring is a form of synthetic monitoring
• Use it alongside (not instead of) real user monitoring
• Test critical paths, not just the homepage
• Use multiple geographic locations

Related Resources

• Uptime Monitoring Guide
• Global Uptime Monitoring
• Pingdom Alternative