Meet LAN Sheriff: See Where Your Network Talks

Your devices talk to the internet constantly, and almost none of it is you. Phones, laptops, TVs, thermostats and doorbells send data to servers around the world all day: apps checking in, telemetry, trackers, ad networks and, occasionally, something that should not be there at all.

LAN Sheriff makes that visible. Run one program, a browser opens, and with no configuration you see in real time what your network is sending, where it goes and who owns the other end.

Why you would run it

• Curiosity: plug in a new smart TV and watch who it calls within seconds.
• Privacy: see who your devices really share data with, instead of taking a company’s word for it.
• Security: notice when a gadget starts talking to a server it has never used before.
• Understanding: get a live map of how everything on your network is connected.

Two ways to watch

Out of the box, LAN Sheriff runs in Deputy Mode: it needs no special permissions, and every connection is tied to the exact application that opened it. Patrol Mode adds packet capture, which reveals DNS lookups and the devices that cannot run software of their own, such as the television, the thermostat and the doorbell. The two run together, and the dashboard shows both.

Private by design

LAN Sheriff runs entirely on your own machine. There is no account, no cloud and no telemetry. It only observes: it never blocks, drops or changes your traffic. Every release ships for twelve platforms, with checksums signed through sigstore and a software bill of materials in every download.

What is next

A version for OpenWrt routers is on the way, so LAN Sheriff can sit where all your traffic already passes, along with a signed build for macOS.

LAN Sheriff is free and open source under the AGPL-3.0 license. Download it from LANSheriff.com or GitHub.