Monitor your REST APIs with full HTTP method support, custom headers, authentication tokens, and request body payloads. Validate responses and track performance.
APIs are the backbone of modern software architecture. Mobile applications, single-page web apps, microservices, third-party integrations, IoT devices, and automated workflows all communicate through API endpoints. When an API endpoint goes down or starts returning errors, the impact is not limited to one page or one user - it can cascade across your entire ecosystem, breaking mobile apps, disrupting partner integrations, halting automated processes, and ultimately causing data loss or revenue damage.
Traditional website monitoring tools are insufficient for API monitoring because they typically only send GET requests and check for HTTP 200 responses. But real-world APIs use POST, PUT, PATCH, and DELETE methods with custom headers, authentication tokens, and structured request bodies. A payment processing endpoint that works perfectly for GET requests might be completely broken for POST requests - and you would never know unless your monitoring matches the actual usage patterns of your API consumers.
UptimeMonitorX provides developer-grade API endpoint monitoring that mirrors how your APIs are actually consumed. Send custom HTTP methods with any combination of headers and request body to your endpoints on every check. Validate that the response status code is correct, the response time is acceptable, and the response content contains expected data. All of this runs automatically at your configured interval, with instant alerts the moment something breaks.
Monitor API endpoints using any HTTP method - GET, POST, PUT, PATCH, DELETE, or HEAD. Test your endpoints with the exact same HTTP verb that your client applications, mobile apps, and frontend code use in production, ensuring you catch method-specific failures that GET-only monitors would miss.
Send custom HTTP headers with every API check, including Authorization tokens (Bearer, Basic, API key), Content-Type headers, Accept headers, and any application-specific headers your API requires. Monitor authenticated endpoints, protected admin APIs, and token-gated resources with full header customization.
Include JSON, form data, or raw request bodies in your API health checks for POST, PUT, and PATCH endpoints. Test that your API correctly processes input data, validates request payloads, and returns expected responses when receiving actual data rather than empty requests.
Define the exact HTTP status codes that indicate a healthy API response. Monitor for incorrect response codes such as 500 Internal Server Error, 502 Bad Gateway, 503 Service Unavailable, 401 Unauthorized, or 403 Forbidden. Trigger alerts only when the API returns an unexpected status code.
Track API response times with millisecond precision on every check. Visualize response time trends on interactive graphs to identify performance bottlenecks, slow endpoints, or degradation caused by database queries, external service calls, or infrastructure limitations.
Combine API monitoring with keyword verification to validate that API responses contain expected fields, values, or data structures. Detect cases where the API returns a 200 OK status but the response body is empty, malformed, or missing critical data that downstream consumers depend on.
Monitor external APIs that your application depends on - payment gateways, shipping providers, email services, social media APIs, and other third-party integrations. Get alerted when a dependency goes down so you can activate fallbacks or communicate proactively with your users.
Verify that your webhook endpoints are online, accepting connections, and processing incoming payloads correctly. Send test payloads as POST requests with the appropriate headers and body to confirm your webhook handlers are functional and ready to receive events from external services.
Yes. UptimeMonitorX allows you to add any custom HTTP headers, including Authorization headers with Bearer tokens, Basic auth credentials, or API keys. Your authentication headers are sent with every monitoring check to ensure the endpoint is tested as your real clients would access it.
UptimeMonitorX supports GET, HEAD, POST, PUT, PATCH, and DELETE methods. This covers all standard REST API operations, allowing you to monitor CRUD endpoints, webhook receivers, RPC-style APIs, and any other HTTP-based service.
Absolutely. For POST, PUT, and PATCH requests, you can specify a JSON request body that will be sent with every check. UptimeMonitorX automatically adds the Content-Type: application/json header when a request body is provided, simulating a real API client call.
Each monitoring check sends a single HTTP request to your API endpoint at the configured interval. If your API has strict rate limits, choose a longer check interval (5, 10, or 15 minutes) to stay well within your rate limit budget while still monitoring availability effectively.
Free plan includes 3 API monitors with custom methods and headers. No credit card required.
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