What Does Your IP Address Reveal?

Every website you visit logs your IP address. It appears in their server logs the moment your browser connects. Understanding what that number reveals — and what it doesn't — is the first step to knowing your online footprint.

What an IP address reveals

City accuracy varies because ISPs register IP blocks to a billing region, not your physical location. A subscriber in San Francisco might show as San Jose because that's where the ISP registered the address block.

What an IP address does NOT reveal

• Your name
• Your street address
• Your email
• Which device you're using
• Your browsing history

Tracing an IP to a specific person requires a court order compelling the ISP to disclose subscriber records. No website can do this on its own.

Check any IP from the command line

# Your own IP
curl ipinfo.io

# Any IP
curl ipinfo.io/8.8.8.8

# Structured JSON output
curl -s ipinfo.io/1.1.1.1 | python3 -m json.tool

import requests

def lookup_ip(ip=''):
    r = requests.get(f'https://ipinfo.io/{ip}/json')
    r.raise_for_status()
    return r.json()

# Your own IP
print(lookup_ip())

# Any IP
info = lookup_ip('8.8.8.8')
print(info['org'], info['city'], info['country'])

IPv4 vs IPv6

IPv4 addresses look like 203.0.113.42 — 32-bit numbers with about 4.3 billion possible values. IPv6 addresses look like 2001:db8::1 — 128-bit numbers with effectively unlimited capacity. Both can be active on the same connection simultaneously (dual-stack).

# Check which IP each protocol shows
curl -4 ifconfig.me   # IPv4
curl -6 ifconfig.me   # IPv6

Dynamic vs static IPs

Most home connections have a dynamic IP that changes when you reboot your router or after a period of inactivity. Your ISP recycles the address to another customer.

Static IPs stay fixed. ISPs charge extra for them. They're mainly used for hosting servers or accessing corporate VPNs that allowlist specific addresses.

# Log your IP with a timestamp to track changes
echo "$(date): $(curl -s ifconfig.me)" >> ~/ip-log.txt

VPN and proxy effects

A VPN routes traffic through a server in another location. Every site you visit sees the VPN server's IP, not yours.

VPN providers own or lease IP blocks. Some websites blocklist known VPN ranges — streaming services do this routinely to enforce regional licensing.