Use a reputable 'what is my IP' service or check the WAN/Internet status page in your router.
Step by Step
- Open a browser.
- Use a reputable public-IP lookup service.
- The displayed IPv4 and/or IPv6 address is the public address the service sees.
- You can also sign in to your router and check its Internet/WAN status page.
If That Doesn't Work
- If your provider uses carrier-grade NAT, your router's WAN address may differ from the public address seen on the internet.
- A VPN or proxy can cause websites to see the VPN/proxy address instead of your normal provider address.