What this is for
Your public IP address is the one servers see when you connect. You need it to allow only your own connection through a firewall, for example:
- UFW:
sudo ufw allow from YOUR_IP to any port 22 proto tcp - Your cloud provider's firewall or security group, for SSH or a database port
- An allow list in a WordPress security plugin, Cloudflare Access or an admin panel
Home and mobile connections usually change address from time to time, so an allow list based on a home IP can lock you out later. For SSH, a VPN such as Tailscale or WireGuard is more reliable than allow-listing a changing address.
IPv4 and IPv6
If your connection has both, which one you see depends on how you reached this site. Allow-list both if your firewall and server use both.
Privacy
Your address is shown to you only. It isn't stored by this tool, and the network details come from public registry data.