Free API Tester — A Browser-Based Postman Alternative
Why Use a Browser-Based API Tester?
Postman is powerful, but it can feel heavier than the job requires when you only need a quick request check. FreeDevKit's API Tester keeps the loop lightweight. You can send GET, POST, PUT, PATCH, and DELETE requests with headers, body, and authentication right in the browser without signing up or installing a separate app.
Features That Matter
Color-coded HTTP methods, request and response tabs, Bearer/Basic/API Key auth, request history with auto-save, named collections, and code snippet generation for cURL, JavaScript, Python, and Go all add up to a workflow that actually helps. The point is not just sending a request. It is understanding what happened quickly enough to keep moving.
Built-In CORS Proxy
Browser-based API testing normally fails due to CORS restrictions. FreeDevKit includes a server-side CORS proxy that forwards your requests with rate limiting and SSRF protection built in. That keeps the browser workflow practical even when the target endpoint would otherwise block direct calls.
A Better Way to Debug APIs
The strongest workflow is to start with a simple request, confirm the response shape, and only then add headers, auth, or body details one step at a time. That makes it easier to isolate the part that is actually failing instead of treating every issue as if the entire endpoint is broken.
Good Uses Beyond Manual Testing
The tester is also useful for demos, quick API checks during development, onboarding teammates, and validating request examples before documenting them in guides or READMEs.
Frequently Asked Questions
Test your API in the browser
Open API Tester to send requests, inspect responses, and generate code snippets without installing anything.
Open API Tester