Your connection

whoami

Everything below arrived with the request that fetched this page. Nothing was looked up about you beyond a reverse DNS lookup on your address, and nothing here is stored.

Address

–

Why this is visible

Your address is not a secret and cannot be one. It is the return address the reply is routed to — without it the page could not reach you. Every server you contact sees it, as does every network in between.

What it identifies is usually a network rather than a person: an internet provider, a mobile carrier, an office, a VPN exit, or a shared address that thousands of people are behind at once. It is a real signal, and a much coarser one than it is often made out to be.

The reverse DNS name, if there is one, is a lookup this server performed on your address. It is set by whoever controls that address block, not by you, and it frequently gives away the provider.

How you connected

protocol: –
transport: –
cipher: –
method: –
host asked for: –
source port: –

A current browser negotiates HTTP/2 or HTTP/3 here, over TLS 1.3. The source port is chosen fresh by your machine for each connection and means nothing on its own.

What your browser volunteered

These are the headers this request carried, with a note on what each one actually reveals. Only headers you sent are listed.

Request headers and what each reveals
Header	Value	What it reveals
Reading your request…

reading

From a terminal

$ curl playground.shen.id/ip            # just your address, one line
$ curl playground.shen.id/whoami       # this page, as terminal text
$ curl -s playground.shen.id/api/whoami  # the same data as JSON

What is kept

This page sets no cookies and there is no database of visitors. The figure above is computed from your request and then forgotten.

That is not the same as nothing being recorded. The web server in front of this application keeps an access log, retained for seven days, because a public machine with no logs cannot be debugged. It contains your address, the path you asked for and your user-agent. The radiation feed is built from that same log, with addresses truncated before they are stored, and it only shows requests that no person could have been sent by a link — so a browser loading a real page, like yours, never appears there.