API Tester
Test REST APIs with custom headers, methods, and request bodies.
What does API Tester do?
API Tester is a free online tool for testing REST APIs. Send HTTP requests with any method (GET, POST, PUT, DELETE, PATCH), custom headers, and request bodies. View response status, headers, body with JSON formatting, response time, and size. No installation required.
Use Cases
- •Testing REST API endpoints during development
- •Verifying API responses and status codes
- •Debugging API integration issues
- •Inspecting response headers and timing
- •Testing authenticated endpoints with custom headers
How to Use
- 1Select an HTTP method from the dropdown
- 2Enter the API endpoint URL
- 3Add request headers (key-value pairs)
- 4For POST/PUT/PATCH, enter the request body as JSON
- 5Click "Send" to make the request
- 6View the response status, body, headers, and timing
Frequently Asked Questions
Does this work with CORS-protected APIs?
Requests are subject to CORS restrictions like any browser-based tool. If an API does not allow cross-origin requests, you may need to test with a desktop tool like curl or Postman.
Are my API keys and tokens stored?
No. All requests are made directly from your browser. No data, headers, or credentials are stored or sent to our servers.
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