How to Test REST APIs Online — Complete Guide
Testing REST APIs is a fundamental skill for backend developers, frontend engineers, and API consumers. Use our REST API Tester to send requests and inspect responses right from your browser.
What is a REST API?
REST (Representational State Transfer) is an architectural style for designing networked applications. REST APIs use standard HTTP methods to perform CRUD operations on resources, typically exchanging data in JSON format. Testing these endpoints is essential to verify they work correctly before integrating them into your application.
How to Test a REST API Endpoint
Follow these steps to test any REST API endpoint using our tool:
Step 1: Enter the Request URL
Paste the full API endpoint URL including protocol (https://) and path. For example: https://api.example.com/users
Step 2: Select the HTTP Method
Choose the appropriate method: GET for fetching data, POST for creating, PUT for updating, PATCH for partial updates, DELETE for removing resources.
Step 3: Add Headers
Add required headers like Authorization: Bearer <token>, Content-Type: application/json, or custom API keys.
Step 4: Add Request Body (if applicable)
For POST, PUT, and PATCH requests, provide a request body. Format it as JSON, form data, or plain text depending on your Content-Type.
Step 5: Send and Inspect the Response
Click Send. The tool displays the response status code, headers, and body. Use this to verify your API behaves correctly.
Example: Testing a REST API Endpoint
GET https://jsonplaceholder.typicode.com/posts/1
Headers: {}
→ Response: 200 OK
→ Body: {
"userId": 1,
"id": 1,
"title": "sunt aut facere repellat provident",
"body": "quia et suscipit..."
}Common HTTP Status Codes in API Responses
200 OK
Request succeeded. The response body contains the requested data.
201 Created
Resource created successfully. Typically returned by POST requests.
400 Bad Request
Invalid request format. Check your headers or request body.
401 Unauthorized
Missing or invalid authentication. Check your Authorization header.
404 Not Found
The requested resource does not exist. Verify the URL.
500 Internal Server Error
Server-side error. Check the API server logs.