Last updated: 2026-07-19
What Is API Monitoring?
Definition
API monitoring checks that your API endpoints are available, returning correct responses, and performing within acceptable time limits. Unlike website monitoring which checks that a page loads, API monitoring validates specific HTTP status codes, response bodies (JSON/XML), and response times. API monitoring is essential for microservices, mobile backends, and any service that exposes an API.
Why it matters
Your website can be up while your API is down. The homepage loads, everything looks fine, but your mobile app is broken, your third-party integrations are failing, and your customers cannot log in. API monitoring catches these failures that standard uptime checks miss. For API-first companies, API monitoring is more important than website monitoring.
Example
A team's main website was monitored and reported 100% uptime. But their /api/v2/auth endpoint was returning 500 errors due to a database connection pool exhaustion. The standard uptime check hit the homepage (which does not use the database) and reported everything was fine. After adding a dedicated API monitor for the auth endpoint, they caught the issue in 30 seconds.
How PingWatchdog helps
PingWatchdog monitors HTTP and HTTPS endpoints with configurable expected status codes. You can specify that a 200 response means "up" for your homepage endpoint, while a 401 response is expected for your auth endpoint (indicating it is working but requires authentication). Response time thresholds can trigger degraded performance alerts before an endpoint goes fully down.