API Tester
Free online API testing tool, lightweight interface debugging
Testing APIs in Your Browser
This lightweight API tester lets you send HTTP requests (GET, POST, PUT, DELETE, PATCH) and view responses without installing any software. Set headers, request body, and method. The response viewer shows status code, headers, and body content.
How to Test an API
Enter the API URL, select the HTTP method, add headers if needed, and enter a request body for POST/PUT requests. Click Send to execute. The response shows the status code, response time, headers, and formatted body.
▶Why does my API request fail with a CORS error?
Browser-based API testing is subject to CORS restrictions. If the API server does not include proper CORS headers, the browser will block the response. For testing APIs without CORS, use the cURL command generator instead.
▶Can I test authenticated APIs?
Yes. Add an Authorization header with your token. For Bearer tokens: Authorization: Bearer YOUR_TOKEN. For Basic auth, use the standard Base64-encoded credentials format.