TOOL
Private IP Checker
Paste an address to classify it: private, public, CGNAT, loopback, link-local or reserved.
Processing happens locally in your browser. Nothing you type is sent to BlackhawkHub.
What it tells you
Paste an IPv4 or IPv6 address and the tool classifies it: private (RFC 1918), public, carrier-grade NAT (100.64.0.0/10), loopback (127.0.0.0/8 or ::1), link-local (169.254.0.0/16 or fe80::/10), unique local IPv6 (fc00::/7), documentation, multicast or other reserved ranges.
Why it matters
The classification tells you whether an address is reachable from the internet, only meaningful on a local network, or a special case. It is useful when setting up port forwarding, diagnosing why a device has no internet (a 169.254 address), or checking whether your ISP uses CGNAT, which blocks inbound hosting. Your own private address is shown by ipconfig.
Frequently asked questions
What is a CGNAT address?
An address in 100.64.0.0/10, reserved for carrier-grade NAT. If your router's WAN address is in this range, your ISP applies NAT before you, so inbound port forwarding cannot work. See the public vs private IP record.
Why does my address start with 169.254?
That is a link-local (APIPA) address, which Windows assigns when no DHCP server answers. It means the device has no proper address and no internet.