Free API Tester & HTTP Client Online
Send HTTP requests directly from your browser — test REST APIs with custom methods, headers, and JSON bodies.
How it works
Enter the URL
Type or paste the API endpoint URL.
Set method and headers
Choose the HTTP method and add any required headers (Authorization, Content-Type).
Add request body
For POST/PUT/PATCH, enter a JSON body.
Send and inspect
Click Send. The response status, headers, and body are displayed immediately.
Common use cases
REST API testing
Quick API endpoint testing without installing Postman or Insomnia — great for one-off checks.
Authentication testing
Test Bearer token or API key authentication by adding the Authorization header and verifying the response.
CORS debugging
Test whether an API returns the correct CORS headers for cross-origin requests from the browser.
Webhook inspection
Test webhook endpoints directly to verify they accept and respond to the correct payload format.
Frequently asked questions
Does this use a server proxy?
No — requests are sent directly from your browser using the Fetch API. CORS restrictions apply: the target API must allow browser requests.
Why do some requests fail with CORS error?
The target API doesn't include Access-Control-Allow-Origin headers for browser requests. Server-to-server requests bypass CORS — use curl or a backend service for those APIs.
Are my auth tokens stored?
No — nothing is persisted. Auth tokens and API keys in the headers field stay in the page only for the current session.
What is the request size limit?
The browser's Fetch API has no hard limit, but very large bodies may time out. For large file uploads use the appropriate tool.