REST API Testing Guide
Learn how to test REST API endpoints effectively. Use our free REST API Client to send requests, inspect responses, and debug your APIs directly in the browser.
HTTP Methods Overview
| Method | CRUD Operation | Description |
|---|---|---|
| GET | Read | Retrieve resources from the server |
| POST | Create | Submit new data to create a resource |
| PUT | Update | Replace an existing resource entirely |
| PATCH | Modify | Apply partial updates to a resource |
| DELETE | Delete | Remove a resource from the server |
Setting Headers and Auth
Headers carry metadata about the request — content type, authentication tokens, caching directives, and more. Common headers include Content-Type, Authorization, Accept, and X-API-Key. Our REST client lets you add, edit, and remove headers freely. For authentication, you can select Bearer token, Basic auth, or custom API key headers from a dropdown.
Reading and Validating Responses
After sending a request, inspect the response status code, headers, and body. A 200 OK means success, 201 Created means a resource was created, 4xx codes indicate client errors, and 5xx codes signal server issues. The response body is displayed with syntax highlighting, and you can copy it with one click.
Common Testing Scenarios
API Endpoint Verification
Confirm that your API endpoints return the expected status codes and data structures.
Authentication Flow Testing
Test Bearer tokens, Basic auth, and API key headers to ensure secure access.
Request Body Payloads
Send POST/PUT JSON payloads and verify your API parses and validates input correctly.
Error Handling
Send malformed data or missing fields to verify your API returns appropriate error responses.