HTTP Probe — Which Hosts Are Serving Web Traffic
This takes a list of hostnames and reports which respond over HTTP or HTTPS. It is deliberately shallow — it does not analyse the response, only establishes that something is serving — which is what allows it to cover a large list quickly.
Why run it
For discovery. Organisations accumulate web endpoints far beyond the ones anybody tracks: staging environments, old marketing microsites, management interfaces, services stood up for a project that ended. Feeding your full list of hostnames through a probe reveals which are actually serving, and the surprises are the point — an admin panel answering on a hostname nobody remembered is exactly the sort of thing that appears here and nowhere in your documentation.
Why automate it
New endpoints appear continuously and nobody reports them. A developer exposes a service for a demo, a subdomain gets pointed at a cloud platform, a vendor stands something up on your domain. Scheduled probing diffed against the previous run turns that into a notification, which is the only realistic way to keep track. The reverse case matters too: a host that used to serve and no longer does is either a decommission nobody logged or an outage nobody noticed.
What it gives you
An accurate list of what is actually serving web traffic under your names, maintained automatically. It is the difference between the inventory you believe you have and the one that exists.