To see every device on your network you have three options: your router's device list, the tools already on your computer (arp -a and its relatives), or a network scanner that sweeps the whole subnet. The first two are free and immediate. They show only part of the picture, though. The scanner is the one that gives you the complete list with IP address, MAC address, vendor and name.
1. The device list in your router
Type your router's address into a browser, usually 192.168.1.1 or 192.168.0.1 (it's printed on a sticker on the box). After logging in, look for a section called Attached Devices, Connected Devices or DHCP Clients. You get a table of everything the router is currently handing an address to: IP, MAC and sometimes a name.
This is the fastest route, but it has gaps. Guest networks and second access points are often missing, devices that left stay listed for days, and the names are frequently blank or cryptic (android-3f9a). Good enough for a first look. Not good enough for "what actually is that".
2. Built-in tools: arp -a on Mac, Windows and Linux
Every computer keeps a table of the devices it has recently talked to, the ARP cache. You can read it directly:
- Mac:
arp -ain Terminal - Windows:
arp -ain Command Prompt, orGet-NetNeighbor -AddressFamily IPv4in PowerShell - Linux:
ip neigh
You get IP addresses with their MAC addresses. The catch: only devices your computer has exchanged data with recently are in there. The printer that has been asleep for hours isn't.
To fill the table, ping every address in the subnet first. Your own address and the netmask show up with ifconfig en0 (Mac), ipconfig (Windows) or ip addr (Linux). If you are 192.168.1.23 with the mask 255.255.255.0 (also written /24), the subnet is 192.168.1.x, which is what the loops below assume. A different mask means a larger subnet, and the loop has to cover more addresses.
Mac and Linux:
for i in $(seq 1 254); do ping -c 1 192.168.1.$i >/dev/null 2>&1 & done; wait
arp -aWindows:
for /L %i in (1,1,254) do @ping -n 1 -w 100 192.168.1.%i >nul
arp -aAfterwards arp -a lists everything your computer reached over ARP while pinging. Devices that ignore pings (some cameras and smart plugs do) usually show up anyway, because the ARP request comes before the ping. Anything asleep or off the network is still missing. We have covered the built-in tools in more depth for scanning a network on Windows and on Linux. macOS no longer ships a graphical scanner at all; we compared nine that fill the gap.
3. What the list still doesn't tell you
A line like 192.168.1.57 a4:83:e7:2b:19:0c doesn't say whether that is the TV or the kids' tablet. Two clues help.
The vendor is encoded in the first three blocks of the MAC address. a4:83:e7 belongs to Apple. Our MAC address lookup turns an anonymous row into "some Apple device".
The hostname is the other one. Many devices announce it over mDNS (Bonjour) or DHCP, such as living-room-tv or Christofs-MacBook. On a Mac, dns-sd -B _services._dns-sd._udp lists the services announcing themselves on the network.
Looking both up by hand for twenty devices takes longer than the scan itself.
4. A network scanner does all of it in one pass
A scanner pings the subnet, queries ARP, mDNS and NetBIOS, looks up the vendors and ends with one table: IP, MAC, vendor, name, device type, open ports. On the command line, nmap -sn 192.168.1.0/24 finds the hosts; open ports need a second run without -sn. Graphical tools show both without the typing.
DeviceShelf is one such scanner for Mac, Windows and Linux. It finds every device on your LAN and Wi-Fi, names it by vendor, hostname and type, and remembers the names you give things for the next scan. Everything runs locally, with no account, and nothing leaves your machine. How a scan works technically and what it shows beyond the router list is on our page Network scanner: see every device on your Wi-Fi and LAN. For the other tools out there, see the comparison.
5. IP addresses change, names stay
A device's IP address is handed out by the router over DHCP and can change after any restart. If you want the printer at the same address every time, set up a DHCP reservation for its MAC address in the router. The IP then stays fixed without touching the device.
The MAC address, by contrast, is stable, with one exception: phones and laptops have used a random MAC address per Wi-Fi network since iOS 14, Android 10 and recent Windows builds. The same phone can therefore show up as a new, unknown device after a change. Why that happens and what to do about it has its own guide.
That's why it pays to name the devices you found once and keep the list. On the next scan only what is genuinely new stands out. If a device is left over that you cannot place: how to identify an unknown device on your network.
Common questions
Why is a device missing from the list? It's asleep, on the guest network or on another subnet (behind a second router, for example). A scanner that runs regularly also catches devices that are only awake now and then.
How do I find my printer's IP address? Look for the vendor (HP, Brother, Canon, Epson) or a hostname containing the model name in the list. Most printers also show their IP in their own menu under Network.
Can I do this from my phone? Yes. DeviceShelf is available for iPhone and Android, and the router list opens in any browser. The ping trick needs a computer, though.