Open almost any router admin page and you will see a field called WAN IP, "Internet IP," or "External IP." It sits next to a different number labelled LAN or local. Most people never need either, until they set up remote access, call ISP support, or wonder why two IP checks disagree.
This post explains what a WAN IP address is: the word itself, where the address lives, how it relates to the public IP that websites see, and when you should actually care about it. If you want a step-by-step check for shared ISP addressing, use How to Tell If You're Behind CGNAT instead. This page is the plain-language background.
Short answer
Your WAN IP is the address your router uses on its internet-facing side, toward your ISP. Every device in your home talks to the router over the LAN. The router talks to the outside world over the WAN.
On a simple home connection, the WAN IP and the public IP that sites see are the same number. On some ISP setups they are not, and that difference is useful information rather than an error.
WAN vs LAN in one minute
Your router has two sides:
- LAN (local area network). The inside. Phones, laptops, TVs, and smart plugs get local addresses here, usually from ranges like
192.168.x.xor10.x.x.x. These addresses only mean something inside your home. - WAN (wide area network). The outside. This is the port or link that connects to the modem, fiber box, or ISP line. The router gets one address on this side from your provider.
When your laptop loads a web page, the request leaves on the LAN, the router rewrites it so it appears to come from the WAN address, and the reply comes back the same way. That rewriting is NAT (network address translation).
So "WAN IP" is not a special kind of address. It is simply which side of the router the address belongs to. For the difference between local and internet-routable ranges, see Public vs Private IP Address Explained.
Where to find your WAN IP
The WAN IP lives on the router, so you read it there, not on your phone or laptop.
- Open the router admin page in a browser. Common addresses are
192.168.1.1,192.168.0.1, or the address printed on a sticker on the device. Many ISPs also offer an app. - Log in with the admin password (not your Wi‑Fi password, unless they happen to match).
- Look for a Status, Internet, or WAN page. The field may be called WAN IP, Internet IP, IPv4 address, or External IP.
Your computer's network settings will not show it. ipconfig on Windows or ip addr on Linux shows the device's LAN address. The "default gateway" shown there is the router's LAN address, not its WAN address. Mixing those two up is the most common source of confusion.
WAN IP vs public IP: same or different?
The public IP is the address the internet actually sees when your traffic arrives. You can read it from outside with the What Is My IP homepage, because a remote service just reports where your request came from.
Compare the two numbers:
- Same number. Your router holds a unique public IPv4 on its WAN. This is the classic home setup. Port forwarding and remote access can work directly.
- Different number, WAN looks private. If the WAN field shows something like
100.64.x.x,10.x.x.x, or192.168.x.x, there is another layer of NAT between your router and the internet. That layer is either a second router in your home (double NAT) or your ISP sharing one public address across many customers (CGNAT). What Is CGNAT? Shared Public IP Explained covers the ISP case. - Different number, both look public. Less common. It can happen when traffic is routed through a VPN on a specific device, a business gateway, or a proxy. A VPN changes the public IP sites see for that device without touching your router's WAN. See What a VPN Changes on Your Visible IP.
Rule of thumb: trust the web check for "what sites see," and trust the router for "what my line was given." You need both numbers to understand a mismatch.
Does the WAN IP change?
Often, yes. Most home plans hand out the WAN address dynamically. It can change after a router reboot, a long outage, a modem swap, or simply when the ISP's lease expires. A fixed WAN address is usually a paid static IP option.
If you rely on the number for anything, re-check it rather than assuming. Static vs Dynamic IP for Home Internet explains the trade-offs.
IPv6 changes the picture a little
With IPv6, your router may show a WAN IPv6 address and a delegated prefix for the LAN. Devices at home then get their own globally routable IPv6 addresses, so there is less NAT and the "one WAN address for everything" idea fades. Your WAN IPv4 can still be shared or private while IPv6 works end to end. If an IP check shows an IPv6 address, that is normal. IPv4 vs IPv6 for Normal Users has the basics.
When the WAN IP actually matters
You can ignore the WAN field for everyday browsing, streaming, and video calls. It becomes useful when:
- Setting up remote access or a home server. Port forwarding only helps if the router's WAN is the real public address. If it is not, read CGNAT and Port Forwarding: Why It Fails before spending an evening on router rules.
- Using dynamic DNS. DDNS services follow your changing address. They work best when WAN and public IP match.
- Talking to ISP support. Giving the agent both your WAN IP and the public IP from a web check speeds things up. ISP Lookup shows which provider and network the public address belongs to.
- Diagnosing double NAT. A private-looking WAN with a second router in the house is a quick thing to fix by putting one device in bridge or access-point mode.
Is it safe to share your WAN IP?
Treat it like your public IP. When the two match, they are the same thing: an address any website you visit already sees. It points to your connection and, via databases, to an approximate region and provider. It does not reveal your street address or name to a random person. Still, only give it to support staff or a service you are deliberately configuring. What Your IP Address Reveals goes deeper.
Bottom line
A WAN IP is the address on the outside of your router, given to you by the ISP. The LAN side is for your devices. When the WAN IP matches the public IP on the What Is My IP homepage, your line has its own public address. When it does not, something in between (a second router or the ISP) is doing extra NAT. That single comparison explains most "why do my two IP numbers disagree" questions, and it is the first thing to check before port forwarding, DDNS, or a support call.