What Is My IP Address? IPv4 vs IPv6 Explained for Developers
If you've ever debugged a CORS error, set up an IP allowlist, or wondered why req.ip returned something weird in your Express logs, you've run into the same question from a different angle: what actually is an IP address, and which one is "mine"? fastestchecker.com
This post breaks down IPv4 vs IPv6, public vs private IPs, and how to reliably detect a user's IP address in your own code — plus a fast way to check yours right now.fastestchecker.com
TL;DR
IPv4 addresses look like 192.168.1.1 — four numbers, 0-255, separated by dots. There are about 4.3 billion of them, and we've run out.
