LAN Scanner (What's on My Network)
See which devices on your network answer a browser. An estimate, not a scan.
How this test works
The page works out your local subnet, then asks every address on it for a web page and times the answer. Three outcomes are possible and only two of them are evidence: something answers, which means a device is there and serving a web interface; the connection is actively refused, which means something is there to refuse it; or nothing comes back at all, which is no evidence either way. That third case is what other browser-based network tools quietly misreport — a silent address is not an empty address. Discovery runs against one port across the subnet, and only addresses that showed life get tried on a few alternates, so the number of requests stays proportional to what is actually there. Before any of it runs, the subnet is checked against the private ranges. Finally the result is sanity-checked: browsers increasingly reject requests to local addresses outright, and an instant rejection looks exactly like a device saying no, so when nearly every address appears alive the page reports that the browser blocked the measurement rather than inventing a network full of devices.
What the results mean
- Network looked at
- The subnet derived from your local address, written as a /24. This is the range the requests went to, and nothing outside it was contacted.
- Devices that answered
- Addresses that either served something or actively refused the connection. Both mean a device is switched on at that address. This is a floor, not a total.
- Serving a web page
- Addresses that returned an HTTP response rather than a refusal. Routers, printers, network storage and cameras almost always do; laptops and phones almost never do.
- Router
- Whether the .1 address answered. Many routers do not serve their admin page on port 80, so no answer here is common and does not mean the router is missing.
Common problems and fixes
- Your local address could not be detected
- Browsers replace the local address with a random .local name to stop pages doing exactly this, and it is a deliberate privacy protection with no way around it. Find the address on your own machine — network settings shows it — and enter it in the box. The subnet is worked out from there.
- It says the browser blocked the requests
- Chrome's Private Network Access rules reject requests from a public page to local addresses, and every address then looks identical. Firefox is generally more permissive. This is a browser policy rather than anything wrong with your network, and it is not something a web page can ask permission for.
- Nothing answered at all
- On guest wifi this is usually client isolation, which blocks device-to-device traffic by design. On a normal network it more often means the devices present have no web interfaces, which is entirely ordinary for a house of laptops and phones.
- You know there are more devices than it found
- You are right, and that is expected. Anything that does not answer HTTP is invisible to this method — which is most consumer devices. A proper network scanner running on your computer sees them because it can do things a browser cannot.
Frequently asked questions
Why does this find fewer devices than an app on my phone?
Because an app can do things a web page cannot: send its own packets, read the address table, watch service announcements, and try ports browsers refuse to open. A browser can only make web requests. What you get here is the subset of your network that answers a web request, which is genuinely useful and genuinely partial.
Is this scanning my network for open ports?
No, and it could not be. Browsers block most ports outright, cannot report why a connection failed, and never expose a service banner. This looks at one port for discovery and a few common web ports on addresses that already answered. It cannot tell you what service is behind an address or whether a port is filtered.
Can this be pointed at a network that is not mine?
No. Only private ranges are accepted, and the check happens before any request is sent. A public address is refused with an explanation rather than probed.
Does anything I find get sent anywhere?
No. The requests go from your browser to your own network directly, and the results are rendered in the page. No address or count leaves the tab, and the exportable summary carries counts only.