API Tester lets you send HTTP requests (GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS) to any endpoint directly from your browser. Add custom headers, a JSON or form-encoded body, authentication tokens, and query parameters. Inspect the response status code, headers, body, and timing. Perfect for exploring APIs, debugging integrations, and testing webhooks without leaving your browser.
How it Works
1Enter the request URL and select the HTTP method.
2Add headers, query parameters, and a request body as needed.
3Click Send — the request is made through a CORS proxy if the endpoint doesn't allow browser requests.
4Inspect the response: status code, headers, formatted JSON body, and response time.
Frequently Asked Questions
Why do some API requests fail with CORS errors?
Browsers enforce Cross-Origin Resource Sharing (CORS) — APIs must explicitly permit requests from browser origins. Many APIs only accept requests from server-to-server calls, not from browsers. EasyDevKit routes requests through a proxy that bypasses CORS, allowing you to test most APIs. Note: APIs that check the Origin or Referer header may still block proxied requests.
Can I test authenticated APIs (Bearer token, API key)?
Yes. Add an 'Authorization: Bearer YOUR_TOKEN' header for OAuth APIs, or add your API key as a header or query parameter as required by the specific API. Headers are transmitted as entered.
Is it safe to enter sensitive API keys in this tool?
Keys entered in the tool are used only for the current request and are not stored or logged. However, as a precaution, avoid entering production credentials with broad permissions. Use read-only or test-environment API keys for browser-based testing.
Can I send multipart form data or file uploads?
The tool supports application/json and application/x-www-form-urlencoded request bodies. Multipart form-data (file uploads) is not currently supported. Use curl or a desktop tool like Postman for file upload testing.