API Tester

An API tester is a tool that lets you send HTTP requests (GET, POST, PUT, DELETE, PATCH) to any REST API and inspect the response. It's essential for developers building, debugging, or exploring APIs. This tool works entirely in your browser — no download or account needed.

Yes. This API tester provides the core features you need — method selection, custom headers, request body editor, JSON syntax highlighting, response timing, and request history — all for free in your browser. No account creation, no desktop app install, and no usage limits.

CORS (Cross-Origin Resource Sharing) is a browser security feature that blocks requests to APIs that don't explicitly allow browser access. If you get a CORS error, the API works fine — it just doesn't allow direct browser requests. Use the API from your server-side code, or test with curl from a terminal instead.

Requests go directly from your browser to the API endpoint — nothing passes through our servers. Request history is stored only in your browser's local storage and never transmitted anywhere. You can clear history at any time.

GET, POST, PUT, DELETE, and PATCH — the five most common REST API methods. You can add custom headers and a JSON body for POST, PUT, and PATCH requests. Responses are automatically formatted with JSON syntax highlighting.