Developer tools · Case study
http.avenash-kumar.com
Check any URL. See what it really returns.
The problem
Why this needed to exist
Browser-based HTTP checkers hit CORS walls and cannot see real server-side headers and timing. If you need to check what an API actually returns, the browser gets in the way.
Testing webhooks is worse. You need a public server to receive them, so most developers end up deploying something temporary just to see a payload arrive.
What I built
The product
The inspector checks any http or https URL with GET, HEAD, POST, PUT, PATCH, DELETE, or OPTIONS, and reports real status, headers, body, size, total time, and time to first byte, all measured by the Worker. The redirect chain shows up to 5 hops with status and location for each one, and cookies come back from set-cookie headers with a copy as cURL option.
A temporary webhook inbox gives you an endpoint valid for 24 hours, with live capture and a simulate button, so you can test webhooks without a public server. Recent inspections are stored in D1 so you can come back to a result.
How it works
Under the hood
The Worker performs the HTTP request server-side, so browser CORS rules never apply, measures real timings, and stores inspection history in D1. Private and local addresses are blocked to avoid server-side request forgery.
One honest limit, stated on the site: Workers fetch does not expose DNS, TCP, or TLS timing, or the TLS version and cipher for the outgoing connection. The app reports total time, time to first byte, and download time, and shows DNS, TCP, and TLS as not available. It does not invent those numbers.
Results
Where it stands
- Server-side inspection for any public URL, with real status, headers, body, and timing.
- Redirect chain up to 5 hops, cookies, and copy as cURL.
- Webhook inbox with a 24 hour endpoint, live capture, and a simulate button.
- Light and dark mode, with a toggle that remembers your choice.