Success
200 OK: Verify the correct response body and data.
201 Created: Verify the resource, location, and returned identifier.
204 No Content: Verify the change completed with no response body.
FREE API TESTING TOOL
HTTP Status Code Guide for API Testing
Use this quick reference to understand common API response codes and what to verify during testing.
Client errors
400 Bad Request: Validate malformed input handling.
401 Unauthorized: Validate missing or invalid credentials.
403 Forbidden: Validate authenticated users without permission.
404 Not Found: Validate unknown resources do not leak data.
409 Conflict: Validate duplicate or conflicting state.
422 Unprocessable Content: Validate field-level business rules.
429 Too Many Requests: Verify rate-limit behavior and retry guidance.
Server errors
500 Internal Server Error: Verify a safe error response without implementation details.
502 Bad Gateway: Check upstream dependency or gateway behavior.
503 Service Unavailable: Verify maintenance or overload behavior and retry guidance.
504 Gateway Timeout: Verify timeout handling for slow dependencies.