Can this REST API tester call any API?

It can call APIs that allow browser requests through CORS. If an API blocks browser access, use the generated cURL command from your terminal or configure CORS on the API you control.

Are my API requests stored by NitroClaw?

No. Requests are sent directly from your browser to the URL you enter. NitroClaw does not proxy, store, or log request URLs, headers, bodies, or responses from this tool.

Can I add authorization headers?

Yes. Add any header name and value in the headers table, including Authorization, Content-Type, Accept, and custom API keys. Be careful when testing sensitive production APIs in shared environments.

Why did my request fail with a CORS error?

A CORS error means the target API did not allow your browser origin to read the response. The request may work from a backend service or terminal because CORS is a browser security policy.

Browser-based REST API testing

Free API Tester Online

An API tester online lets you send REST requests from your browser and inspect the response status, headers, body, and timing. Use it to debug endpoints quickly, generate a matching cURL command, and verify API behavior without installing a desktop client.

7

Methods

JSON

Response view

cURL

Export

Request

Method

Endpoint URL

TimeoutInclude cookies

Headers

BodyBody disabled for GET

cURL

curl \
  -i \
  -X \
  GET \
  'https://jsonplaceholder.typicode.com/posts/1' \
  -H \
  'Accept: application/json' \
  -H \
  'Content-Type: application/json'

Response

Send a request to inspect the response.

You will see status, timing, headers, formatted JSON or text, and any browser-level error details here.

Security note

This tool runs in your browser and does not proxy requests through NitroClaw. Avoid pasting production secrets on shared computers, and use the generated cURL command for APIs that block browser CORS access.

Frequently Asked Questions

What is an online API tester?

An online API tester sends HTTP requests to REST endpoints and shows the response status, headers, body, and timing in one screen.

Why do some requests fail in the browser?

Some APIs block browser-based requests with CORS. When that happens, copy the generated cURL command and run it from your terminal or configure CORS on the API.

Does NitroClaw store my request data?

No. This tool sends requests from your browser directly to the endpoint you enter. NitroClaw does not proxy, log, or store your URLs, headers, bodies, or responses.

Can I send JSON request bodies?

Yes. Add Content-Type: application/json in the headers table, paste JSON into the body editor, and send the request with POST, PUT, PATCH, or DELETE.

What does the generated cURL command do?

The cURL command mirrors the selected method, URL, enabled headers, and request body so you can repeat the same API test from a terminal or CI environment.