Runs 100% in your browser — nothing is uploaded
Network & Web

REST API Tester

Send HTTP requests and inspect status, headers, and body — a lightweight Postman alternative in your browser.

REST API Tester
Client-side

About this tool

Sometimes you just need to fire off a quick GET or POST and see what comes back, without opening a full desktop client. This tool lets you build and send HTTP requests directly from your browser using the native fetch API: pick a method, enter a URL, add custom headers via a key-value editor, and supply a body as JSON, form-data, or raw text.

The response panel shows the HTTP status and status text, every response header in a readable table, the response body (automatically pretty-printed if it parses as JSON), and the round-trip time in milliseconds. For form-data bodies, key=value lines are parsed and sent as a real multipart FormData payload; for JSON bodies, a Content-Type header is set automatically.

Because this runs entirely client-side with no proxy server, it is bound by the same CORS rules your browser enforces on any web page — it can only successfully call APIs that send the appropriate Access-Control-Allow-Origin headers back. For convenience, your last request configuration is saved to localStorage — response data is never persisted, only the request shape you typed.

FAQ

Why do I get a network error when the API should be reachable?
This is almost always CORS. Browsers block cross-origin responses unless the server explicitly sends Access-Control-Allow-Origin headers permitting your page's origin.
Is my request data sent to any server other than the API I specify?
No. Requests go directly from your browser to the URL you enter using the native fetch API — there is no proxy or intermediary server.
What gets saved to localStorage?
Only the request shape — method, URL, headers, body, and body type. Response data is never persisted; it exists only in memory for the current page session.
How does form-data body input work?
Enter one key=value pair per line while "Form Data" is selected. Each line is parsed and appended to a real FormData object, sent as a multipart/form-data request.
Can this tool replace Postman entirely?
For quick one-off requests against CORS-friendly APIs, yes. For APIs without CORS headers or advanced features like collections and test scripts, a desktop client is still the better fit.