How REST API Tester Works

Enter the target URL, choose an HTTP method, and optionally add headers and a request body. When you click Generate, the tool sends the request from the server, captures the response, and presents a compact summary (status, timing, and size) along with the full response body. This makes it easy to validate that your endpoint behaves as expected before you integrate it into your application.

Step-by-step

• 1) Provide a URL: Paste the full endpoint URL, including any query string you want to test.
• 2) Select a method: Choose GET, POST, PUT, PATCH, DELETE, HEAD, or OPTIONS depending on the API action.
• 3) Add headers: Include headers such as Authorization, Content-Type, or custom keys. You can paste headers as JSON for speed.
• 4) Add a request body: For POST/PUT/PATCH, provide JSON or text payloads to simulate real client requests.
• 5) Review results: Inspect the HTTP status, response headers, timing, and the response body. Copy or download the output for documentation.

Key Features

Multiple HTTP Methods

Test common REST patterns by switching between methods like GET for retrieval, POST for creation, PUT/PATCH for updates, and DELETE for removal. HEAD and OPTIONS can help you verify CORS and server capabilities without downloading a full payload.

Flexible Headers Input

APIs often require authentication and versioning through headers. Add Authorization tokens, API keys, Accept headers, and custom values. The tool also normalizes header formatting to reduce mistakes when you paste from docs or code snippets.

Request Body Support

Send JSON payloads for endpoints that accept request bodies. This is useful for validating schema changes, checking validation messages, and reproducing bugs reported by clients. You can keep your payload small or paste a realistic sample from your application.

Readable Response Output

See status code, response time, and approximate response size at a glance. The response body is displayed in a monospaced text area so it stays copy-ready for bug reports and tickets, even when the output is large or contains structured data.

Safety-minded Request Handling

The tester is intended for public endpoints. For security, it blocks requests to common private network targets and local addresses. This reduces the risk of server-side request forgery patterns while still supporting standard HTTP and HTTPS testing for typical REST APIs.

Use Cases

• API debugging: Reproduce an error quickly by sending the same method, headers, and body your client uses.
• Integration testing: Validate endpoints during development to confirm payload shape and status behavior.
• Authentication checks: Verify tokens, API keys, and permission scopes by testing protected routes.
• CORS verification: Use OPTIONS requests and inspect headers to confirm cross-origin configurations.
• Performance smoke tests: Compare response times across environments or after server-side changes.
• Documentation validation: Confirm that examples in your docs still work and return the expected fields.

Whether you are building a backend service, consuming a third-party API, or maintaining internal microservices, a lightweight REST API tester helps you confirm behavior and communicate issues with clear, reproducible request details.

Optimization Tips

Start with minimal headers

When debugging, begin with only the required headers (for example, Authorization and Content-Type). Add optional headers one by one to isolate problems such as content negotiation mismatches or caching behavior.

Use realistic payload samples

For create or update endpoints, use a sample body that mirrors real data. This helps you catch validation edge cases, missing required fields, and serialization issues before they reach production.

Watch for status patterns

Use status codes as a quick diagnostic signal. 4xx responses usually indicate client-side issues (missing auth, invalid body), while 5xx responses point to server-side failures that deserve logs and monitoring investigation.

FAQ