HTTP API Test Online - Debug GET/POST/PUT/DELETE Requests
GET / POST / PUT / DELETE
About HTTP API Testing
Send HTTP requests such as GET, POST, PUT, DELETE and PATCH with custom Headers and Body. When an API returns JSON, use JSON Formatter to organize the structure, and handle request parameters with URL Encode/Decode; to look up common ports, use Port Lookup.
Use Cases for HTTP API Testing
Backend API debugging: quickly verify the response format and status code. Frontend integration: simulate requests without a backend environment. Webhook testing: verify that a webhook callback URL correctly receives and processes data. Performance assessment: get a rough sense of API performance from response time.
FAQ
What is the difference between GET and POST requests?
GET appends parameters to the URL and is suited to data retrieval, with a limited request length; POST puts data in the request body and is suited to submitting large payloads. Their semantics differ: GET is idempotent (repeated requests give the same result), while POST is not (each call may produce a different result).
What are the common HTTP status codes?
2xx success: 200 OK, 201 Created; 3xx redirect: 301 permanent, 302 temporary; 4xx client error: 400 Bad Request, 404 Not Found; 5xx server error: 500 Internal Server Error, 502 Bad Gateway.
Why do I get a CORS error?
CORS (Cross-Origin Resource Sharing) is a browser security policy. When a frontend page requests an API on a different domain, the target server must allow cross-origin access. If you hit this error, resolve it via server configuration or a proxy.
What is a RESTful API?
A RESTful API is an interface design style based on HTTP methods: GET retrieves a resource, POST creates one, PUT fully updates it, PATCH partially updates it and DELETE removes it. This tool supports all of these methods for debugging various HTTP APIs.