An IP address (Internet Protocol address) is a unique numerical label assigned to a device or network interface so computers can find each other and exchange data. Without IP addresses, routers would not know where to send web pages, emails, or video streams.
This guide explains what an IP address is, public vs private addresses, IPv4 vs IPv6, and how to check your public IP with free tools—starting with What Is My IP? on IPtoolbox.
IP address in plain language
Think of an IP address as a return address for internet traffic. When you open a website, your device sends requests that include (or are associated with) an address the internet can route to. The site’s servers send responses back to that address. The details are handled by routers, your ISP, and protocols like TCP/IP—but the idea is simply: every connection needs a destination label.
There are two major versions you will see:
- IPv4 — classic dotted form, e.g.
203.0.113.42 - IPv6 — longer hexadecimal form, e.g.
2001:db8::1
Public vs private IP addresses
Not every IP is visible on the global internet.
Public IP
Your public IP is the address the outside world sees. It is assigned by your internet service provider (ISP) to your home, office, mobile connection, or data center. Websites, game servers, and APIs see this address (or a shared address, if you are behind carrier-grade NAT).
Check yours instantly: What Is My IP? · What's My IP Location?
Private IP
Private IPs are used inside local networks—your router might give your laptop
192.168.1.10 while many devices share one public IP via NAT (Network Address Translation). Common
private ranges include:
10.0.0.0–10.255.255.255172.16.0.0–172.31.255.255192.168.0.0–192.168.255.255
Private addresses are not meant to be reachable directly from the public internet. That is why “what is my IP” sites show your public address, not your laptop’s LAN address.
IPv4 vs IPv6 (why both exist)
IPv4 uses 32-bit addresses—about 4.3 billion unique values. That sounded huge in the early internet; today it is not enough for every phone, sensor, and server. IPv6 uses 128-bit addresses, providing a vastly larger space and simpler features for modern networks.
Many networks run dual-stack: both IPv4 and IPv6. Your device may have both at once. Convert formats with the free IPv4 to IPv6 Converter.
Dynamic vs static IP
- Dynamic — most home connections; the ISP may change your public IP after a reboot or lease renewal.
- Static — fixed address, common for servers and some business plans.
If your public IP changes, bookmarks that “allowlist your IP” may break until you update them. That is normal for residential dynamic addressing.
What your IP can (and cannot) reveal
A public IP can often be associated with:
- Approximate city or region (see the IP Geolocation Map)
- Your ISP or organization
- Sometimes a network type (residential, hosting, mobile)—depending on data sources
It usually cannot show your exact street address to casual lookers. Geolocation databases are estimates. For accuracy notes, read My Location and the map tool’s accuracy section.
How to find your IP address
Fastest method (any device with a browser)
- Open https://www.iptoolbox.app/what-is-my-ip
- Read your public IPv4 (and IPv6 if detected)
- Optionally check proxy/VPN indicators and ISP details on the same page
On Windows (local/private IP)
Open Command Prompt and run ipconfig. Look for “IPv4 Address” under your active adapter. That is
usually a private LAN address—not your public IP.
On Mac
System Settings → Network → your connection, or Terminal: ifconfig / ipconfig getifaddr en0
depending on interface. Again, that is often private; use a browser tool for the public IP.
On iPhone / Android
Wi‑Fi settings show local details; for the public IP, use a trusted site like IPtoolbox in the mobile browser.
Looking up other IP addresses
Sometimes you need context for an IP in a log, email header, or security alert—not your own:
- IP Address Tracker — location and ISP for any IP
- IP Geolocation Map — map-first view
- IP WHOIS Lookup — registry ownership and contacts
- ASN Lookup — which Autonomous System routes the IP
- Bulk IP Lookup — many IPs in one batch
- IP Blacklist Checker — reputation lists
For a deeper dive into network identity, read our guide What Is an ASN?.
Privacy: hiding or changing your IP
People change how their traffic appears online by using:
- VPN — encrypts traffic and exits from the VPN provider’s IP
- Proxy — forwards traffic; privacy and security vary widely
- Tor — multi-hop anonymity network (different threat model)
After connecting a VPN, reload What Is My IP? and Proxy Check to see what the internet observes. Remember: hiding your IP does not make you invulnerable—accounts, browsers, and malware still matter.
Key takeaways
- An IP address labels a network interface so traffic can be routed.
- Public IPs face the internet; private IPs stay on LANs.
- IPv4 and IPv6 can coexist on modern networks.
- Public IP geolocation is approximate—not a GPS pin on your house.
- Use free tools to check your IP, map others, and investigate ownership via WHOIS/ASN.
FAQ
What is an IP address in simple terms?
A numerical label that helps the internet deliver data to the right device or network—like an address on a letter.
Public vs private IP?
Public IPs are visible on the internet. Private IPs stay inside your home/office network behind a router.
How do I find my public IP?
Open What Is My IP?—no install required.
Can someone track me with my IP?
They may see approximate location and ISP. Exact identity typically requires ISP records and legal process.