A public IP address is intended for routing on the public internet. A private IP address is used within a private network and is not globally unique. This distinction explains why your laptop's Wi-Fi address often differs from the address shown by an IP-checking website.
Private IPv4 ranges
RFC 1918 reserves three IPv4 blocks for private networks. Homes, offices, and cloud networks can reuse them independently.
| CIDR block | Address range |
|---|---|
10.0.0.0/8 | 10.0.0.0–10.255.255.255 |
172.16.0.0/12 | 172.16.0.0–172.31.255.255 |
192.168.0.0/16 | 192.168.0.0–192.168.255.255 |
Not every address outside these ranges is public. Loopback, link-local, documentation, multicast, and other special-purpose blocks have separate uses. For example, 127.0.0.1 refers to the local host; it does not identify a connection on the internet.
How a router connects private devices
A home router commonly performs NAT. It tracks connections from private devices and rewrites their source addresses and ports so replies can return through a shared public IPv4 address. Your phone and laptop may therefore show the same result on My IP while keeping different addresses inside your Wi-Fi network.
If the router's internet-facing address is in 100.64.0.0/10, the provider may be using shared address space for carrier-grade NAT. This block is distinct from RFC 1918 private space and is not a normal globally reachable public address. Double NAT can also occur when one private router sits behind another.
Where IPv6 is different
IPv6 uses its own scopes. Link-local addresses in fe80::/10 work on a local link. Unique-local addresses in fc00::/7 are intended for local communications; locally assigned prefixes commonly start with fd. Neither is a substitute for a globally routed public address.
A device may simultaneously have link-local, unique-local, and global IPv6 addresses. It chooses a source address appropriate for a destination. Privacy extensions can create temporary source addresses for outbound traffic. Learn more in the IPv4 vs. IPv6 guide.
How to find each address
- For the address a website sees, open My IP using the connection you want to check.
- For a local address, open your operating system's network settings and select the active Wi-Fi or Ethernet connection.
- For the router's WAN address, check its administration interface if you are authorized to manage it.
- Compare the results with your VPN or proxy configuration in mind. Each destination may see a different exit path.
A normal website cannot directly inspect all of your device's local interface addresses. This site's server reports the source address Cloudflare supplies for the request; it does not enumerate your home network.
Does a public address mean my device is exposed?
No. Reachability also depends on routing, firewall rules, listening services, and provider restrictions. A public address alone is not proof that a port is accessible, and an IP lookup is not a port scan.
Private addressing is not a guarantee of security either. Devices inside the same network, compromised routers, and misconfigured forwarding can still present risks. Manage access with appropriate firewall and application settings for both IPv4 and IPv6.