Online API Tester
Send GET, POST, PUT and DELETE requests to any REST API (headers, query params and JSON body) and inspect the response. Free.
About Online API Tester
The Online API Tester is a REST client that lives in a browser tab. Pick a method (GET, POST, PUT, PATCH, DELETE, HEAD or OPTIONS) type an endpoint, add query parameters and headers as key/value rows, paste a JSON or form body, and send. The response comes back with its status, timing, size, headers and a pretty-printed body.
Requests are relayed through our server rather than issued by the browser, which is what makes it work against APIs that send no CORS headers: the usual reason a fetch from the console fails. The trade-off is that the endpoint sees our server as the client: your own IP address is never revealed to the target, but IP allow-lists on the API side will reject the call.
The proxy is deliberately constrained: public http and https hosts on the standard ports only, up to 40 header rows, a request body of up to 100,000 characters, a 15-second response timeout, and a response body captured up to 200,000 characters with truncation flagged. Redirects are not followed, so a 301 or 302 is shown exactly as returned.
How to use Online API Tester
- Choose the HTTP method and enter the endpoint URL.
- Add query parameters on the Params tab: they are appended to the URL before sending.
- Set your headers on the Headers tab, for example Content-Type and Authorization.
- Paste the request payload on the Body tab for POST, PUT, PATCH or DELETE.
- Click “Send request”, then read the status, timing and size, and switch between the response body and its headers.