GRC Port Scan - GRC Internet Security Port Scanner. Tests for open ports on your external IP address.
What is my IP? - Find out what your IP is. Do not hesitate to open wimip.
whatismyip.cc - External IP Address lookup tool with option to scan the external IP address.
geoiplookup.net - (IPv4 only) Online tool to get accurate IP address information
Skeebus - Skeebus is a macOS menu bar app that displays your current public IP address
IP-Toolbox.com - IP-Toolbox.com is the best site for quick and easy viewing of your public IP address and other related information.