172.16.0.0/12 is a private range (172.16.0.0 to 172.31.255.255)

What it means

172.16.0.0/12 is the middle RFC 1918 private range. Fewer home routers use it, but software does: Docker’s default bridge network is 172.17.0.0/16, so a 172.17.x.x address on a computer usually belongs to a container, not the internet.

RFC 1918 sets aside three ranges (10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16) for networks that are not directly on the internet. Your router hands these out to your phone, laptop and TV, and every home can reuse the same numbers because they are never routed between networks.

When a device with a private address opens a website, the router rewrites the request so it comes from the router’s one public address (network address translation, NAT). That public address is what the Truth Check on our home page shows; the private one stays inside your network.

What to do

• To see the address websites see, open the Truth Check from the same device.
• Your router’s own admin page is usually at the first address in the range, such as 192.168.0.1 or 192.168.1.1 — check the label on the router or its manual.
• A private address on a device does not mean anything is wrong.

Router addresses in this block

172.16.0.1 are common router admin addresses inside this range. Yours is printed on the router or in its manual; you can only reach it from your own network, and we never offer a login page for it.

Sources

1. IANA IPv4 Special-Purpose Address Registry (CC0) · checked 2 Nov 2026
2. RFC 1918