API Tester

A lightweight REST client that runs entirely in your browser. Enter a URL, pick a method, add headers and a body, then inspect the response status, headers, and body with JSON syntax highlighting; requests are saved to a local history.

• Headers 0
• Body

How It Works

This tool uses the browser's built-in fetch() API to send HTTP requests directly from your device; nothing is routed through our servers, so your URLs, headers, tokens, and response data never leave your browser.

• Method & URL: choose a verb (GET, POST, PUT, DELETE, and more) and enter the endpoint you want to call.
• Headers: add any number of key/value pairs, or use the quick presets for common headers like Content-Type and Authorization.
• Body: supply a request payload for methods that accept one; the Format JSON button pretty-prints valid JSON.
• Response: the status code, round-trip time, and size are shown, along with the response headers and a syntax-highlighted body (JSON is automatically formatted).
• History: your last requests are saved in this browser's localStorage; click any entry to reload it into the form.

A note on CORS

Because requests run from the browser, they are subject to Cross-Origin Resource Sharing (CORS) rules; an API must return permissive Access-Control-Allow-Origin headers for the browser to expose its response to this page. If a request fails with a network or CORS error even though the API is reachable, the server has not opted in to cross-origin access; this is a browser security policy and not a limitation of the tool. Public, CORS-enabled test APIs such as jsonplaceholder.typicode.com work out of the box.

Privacy

All processing is client-side; request history is stored only in your own browser and can be wiped at any time with the Clear button.