Send HTTP requests and inspect responses. Pure client-side.
HTTP · REST · debug
Send HTTP requests from your browser to probe APIs: choose method, headers, and body, then inspect the response. A lightweight client for quick checks when you do not want to open a full desktop REST app.
During integration you often need a fast “does this URL return 200 with this header?” loop. An in-browser tester is ideal for public CORS-enabled APIs, staging endpoints that allow your origin, and educational demos. It is not a full replacement for Postman/Insomnia collections, server-side integration tests, or authenticated flows that require secrets you should not paste into a browser tab on a shared machine.
CORS: Browsers enforce Cross-Origin Resource Sharing. A request that works in cURL may fail here if the API does not send matching Access-Control-Allow-* headers for this origin. That is a browser security rule, not necessarily an API outage. Use the CORS Builder when configuring servers you control.
https://).GET, POST, PUT, PATCH, DELETE, …).Content-Type: application/json, Authorization).| Topic | Guidance |
|---|---|
| Secrets | Prefer staging keys; rotate if pasted on a shared computer |
| Idempotency | Be careful with POST/DELETE against production |
| JSON bodies | Validate with JSON Formatter first |
| From docs cURL | Convert with cURL → fetch, then mirror headers here |
Usually CORS, mixed content (HTTPS page calling HTTP), or certificate issues visible only in browsers.
Requests originate from your browser to the target URL (subject to browser rules). See Privacy Policy.
Often yes if the API allows your origin or you disable web security only in controlled local dev browsers — prefer proper CORS on the dev server.