IP Address Lookup — What the Internet Knows About You
See your public IP address, geolocation, ISP, and ASN instantly — then go further: check for WebRTC leaks that bypass VPNs, reveal your browser fingerprint, calculate subnets with the CIDR calculator, and convert between IPv4 and IPv6. Free, no signup required.
What Information Does an IP Address Reveal?
Your IP address reveals more than most people realize. Every website you visit sees:
- Approximate location — accurate to city level in ~60–80% of cases (not your street address)
- Internet Service Provider (ISP) — the company providing your internet connection
- ASN (Autonomous System Number) — the network identifier for your ISP's infrastructure
- Connection type — residential, business, mobile, or VPN/datacenter
What your IP does not reveal: your name, street address, or any personal information.
WebRTC Leak Test — Why It Matters for VPN Users
WebRTC (Web Real-Time Communication) is a browser API used for video calls, voice chat, and peer-to-peer data transfers. A known privacy issue: browsers can expose your real local and public IP address through WebRTC ICE candidates — even when you're connected through a VPN.
This is called a WebRTC leak. It means:
- You connect via VPN → your public IP appears to be the VPN server's IP
- Websites use WebRTC → your real IP leaks through the browser
- Your VPN is bypassed without you knowing
How to fix a WebRTC leak:
- Firefox: set
media.peerconnection.enabledtofalseinabout:config - Chrome/Edge: use an extension like WebRTC Network Limiter
- Use a VPN with built-in WebRTC protection (Mullvad, ProtonVPN)
Browser Fingerprint — Beyond Your IP
Even without your IP, websites can identify you through browser fingerprinting — a combination of attributes that, together, form a nearly unique signature:
| Attribute | What it reveals |
|---|---|
| User Agent | Browser name, version, OS |
| Screen resolution | Device type and display |
| Timezone | Geographic region |
| Language | Browser/system language |
| Do Not Track | Privacy preference signal |
Unlike cookies, browser fingerprinting cannot be cleared and works even in private/incognito mode.
CIDR / Subnet Calculator
CIDR (Classless Inter-Domain Routing) notation expresses an IP network as a single compact string: 192.168.1.0/24. The number after the slash is the prefix length — how many bits are fixed (the network portion).
| CIDR | Addresses | Usable Hosts | Subnet Mask |
|---|---|---|---|
| /30 | 4 | 2 | 255.255.255.252 |
| /29 | 8 | 6 | 255.255.255.248 |
| /28 | 16 | 14 | 255.255.255.240 |
| /27 | 32 | 30 | 255.255.255.224 |
| /26 | 64 | 62 | 255.255.255.192 |
| /25 | 128 | 126 | 255.255.255.128 |
| /24 | 256 | 254 | 255.255.255.0 |
| /16 | 65,536 | 65,534 | 255.255.0.0 |
| /8 | 16,777,216 | 16,777,214 | 255.0.0.0 |
Private IP Address Ranges (RFC 1918)
These ranges are reserved for local networks and are not routable on the public internet:
10.0.0.0/8 → 10.0.0.0 – 10.255.255.255 (16.7M addresses)
172.16.0.0/12 → 172.16.0.0 – 172.31.255.255 (1.05M addresses)
192.168.0.0/16 → 192.168.0.0 – 192.168.255.255 (65,536 addresses)
127.0.0.0/8 → Loopback (localhost)
169.254.0.0/16 → Link-local (no DHCP — APIPA)
If your IP starts with any of these, it is a private IP — visible only within your local network. Your public IP is assigned by your ISP.
IPv4 vs. IPv6
| IPv4 | IPv6 | |
|---|---|---|
| Format | 4 octets: 203.0.113.42 |
8 hex groups: 2001:db8::1 |
| Length | 32-bit (4 bytes) | 128-bit (16 bytes) |
| Total addresses | ~4.3 billion | ~340 undecillion |
| Status | Exhausted (2011) | Actively deployed |
| NAT required | Usually yes | Not required |
IPv4-mapped IPv6 addresses (format ::ffff:x.x.x.x) allow IPv6 systems to communicate with IPv4 services.
What Is an ASN?
An Autonomous System Number (ASN) is a globally unique identifier assigned to a group of IP prefixes operated by a single organization — typically an ISP, university, or large company.
ASNs are used by the Border Gateway Protocol (BGP) to route traffic between autonomous systems on the internet. Examples:
- AS15169 → Google
- AS16509 → Amazon AWS
- AS20940 → Akamai
- AS13335 → Cloudflare
When you see your ASN in the tool above, it identifies which network your IP address belongs to.
Frequently Asked Questions
What is my IP address?
Your IP (Internet Protocol) address is a numerical label assigned to your device by your ISP when you connect to the internet. It identifies your network location, allowing data to be routed to and from your device. The tool above shows your current public IP address automatically — no input required.
How accurate is IP geolocation?
IP geolocation is accurate to the country level in ~99% of cases and to the city level in ~60–80% of cases. It cannot pinpoint your street address or home. Accuracy varies by ISP: some assign IPs geographically; others may assign IPs from different regions.
What is the difference between a public and private IP address?
A public IP is assigned by your ISP and is visible to websites and servers on the internet. A private IP (ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) is used within local networks. Your router has a public IP; your devices have private IPs assigned by the router via DHCP.
Can my VPN hide my IP address completely?
A VPN replaces your real IP with the VPN server's IP for web traffic — but WebRTC leaks can bypass the VPN tunnel and expose your real IP through the browser. Use the WebRTC leak test on this page to verify your VPN is fully protecting you.
What is a DNS leak?
When using a VPN, your DNS queries should go through the VPN's DNS servers. A DNS leak occurs when DNS queries bypass the VPN and go to your ISP's DNS servers instead — revealing your browsing activity and real location to your ISP.
What is the difference between IPv4 and IPv6?
IPv4 uses 32-bit addresses (~4.3 billion total, exhausted globally since 2011). IPv6 uses 128-bit addresses (virtually unlimited). Most networks now support both simultaneously (dual-stack). IPv6 eliminates the need for NAT and supports better security at the protocol level.
