REST API Tester
Construct API requests in-browser and inspect responses with clear CORS and timeout handling.
Requests are sent directly from your browser. Sensitive data is not logged by UtilityStacks.
Requests are sent directly from your browser and must pass target CORS rules. Do not expose secrets or production credentials.
Request preview
https://httpbin.org/get
Multipart/form-data is not supported in this version.
cURL export
curl -X GET "https://httpbin.org/get"
Examples
Select a template and edit it before sending. Requests are not auto-executed.
Use in code
Equivalent API requests in common languages for server-side or script-based workflows.
Send JSON request with fetch
TypeScriptPrimary API
fetch(url, { method, headers, body })
Sends a POST request and parses JSON response.
const response = await fetch("https://api.example.com/users", {
method: "POST",
headers: { "Content-Type": "application/json" },
body: JSON.stringify({ name: "Alice" }),
});
const data = await response.json();
console.log(response.status, data);Reference: Fetch API documentation
How to use
- Choose an HTTP method and enter an https:// or http:// URL.
- Add params, headers, and optional JSON or text request body.
- Send the request and inspect status, headers, and response content.
Use cases
- Validate API endpoint behavior during integration work.
- Inspect CORS, status codes, and response payload formatting.
- Quickly move JSON responses into JSONPath queries.
Limitations and caveats
- Browser CORS restrictions apply; this tool does not bypass cross-origin policy.
- Multipart/form-data is not supported in this initial version.
- Private network and metadata endpoints are blocked for safety.
History
- REST describes architectural constraints for web systems, while many practical APIs use JSON over HTTP patterns.
- Browser-based API clients became popular for quick endpoint checks without local installs.
Source: RFC 9110 HTTP Semantics 路 Fetch Standard 路 MDN CORS guide
Evolution and improvements
- Modern API testing tools emphasize environment safety, request reproducibility, and cross-tool workflows.
- CORS-awareness became essential as browser clients moved from same-origin apps to multi-service integrations.
Source: RFC 9110 HTTP Semantics 路 Fetch Standard 路 MDN CORS guide
FAQ
Why did my request fail with a CORS message?
The target API did not allow cross-origin access from this site. This tool does not bypass browser CORS policy.
Are my Authorization headers stored?
No. Authorization data is held in-memory only for the current session and is not persisted by default.