IP to ISP Lookup - Find the ISP and Network Behind Any IP Address
Enter any IPv4 or IPv6 address to find the Internet Service Provider (ISP) behind it, along with the organization, network type, and ASN that routes it - or press Find my ISP to check your own connection. Free to use, no signup required.
What an IP to ISP lookup tells you
An ISP (Internet Service Provider) is a network that sells internet access - a home broadband company or a mobile carrier. Not every network is one: hosting companies, CDNs, universities and large enterprises run networks and announce their own addresses without selling access to anybody. Both kinds turn up in a lookup, so the result names what it found rather than calling everything an ISP - you will see Internet Service Provider where the network sells access, and Hosting provider or Network operator where it does not.
An IP to ISP lookup maps a single public IP to the provider responsible for it. For any IPv4 or IPv6 address the tool returns:
| Field | What it tells you | Example |
|---|---|---|
| ISP / Network operator | The organization that runs the network this address belongs to, shown with its domain. Called an Internet Service Provider where that network sells internet access, and a hosting provider or network operator where it does not. | Google LLC / google.com |
| ASN | The Autonomous System Number of the network that carries this address. | AS15169 |
| ASN type | How that network classifies its own use. It describes the whole network, not this one address. | BUSINESS |
| Regional registry | The Regional Internet Registry that allocated the AS number. | ARIN |
| Registry country | Where the network was registered - not where the address is in use. | US |
| ASN allocated | When the registry allocated the AS number to its operator. | March 30, 2000 |
| Network route | The block of addresses this one is routed as part of, in CIDR notation. | 8.8.8.0/24 |
| Connection type | How a home connection reaches the internet. Broadband and mobile providers report this; hosting, CDN and corporate networks usually do not. | Cable |
| Anycast | Whether the address is announced from several places at once, as public DNS and CDNs do. A reason geolocation on such an address is unreliable. | Yes |
| IP registered to | The organization the address block is registered to - often the same provider under a different corporate name, occasionally a separate organization. | APNIC Research and Development |
A lookup identifies the network owner, not the individual person behind the address.
A field with nothing behind it is left out rather than filled in with N/A, so a short result is a normal one and not a failed lookup. Connection type is the clearest case: home connections come back as Cable, DSL or Mobile, while hosting, CDN and corporate networks return nothing for it at all - which is itself a useful signal about the kind of address you are looking at.
IP registered to appears only when the address block is registered under a different name from the provider announcing it. Usually that is the same company wearing another hat - Comcast's residential space is registered to "Comcast IP Services, L.L.C." - and occasionally a genuinely separate organization, as with 1.1.1.1, Cloudflare's resolver on a block registered to APNIC.
To list every prefix a network controls or work from an AS number directly, start with the IP to ASN Lookup tool.
When to run an ISP lookup
- Triage suspicious traffic. When you see spam signups, scraping, or brute-force attempts, the ISP and ASN tell you which network the requests come from - a first read before you decide to allow, challenge, or block.
- Apply network-based rules. Teams allowlist or denylist by provider or network type. Identifying the ISP is the step before that decision.
- Investigate fraud and abuse. Abuse often clusters on a handful of providers or hosting networks; the ISP/ASN makes that pattern visible across many IPs.
- Diagnose connection and routing issues. If a user reports slowness, knowing their ISP helps you spot provider- or routing-related causes.
- Tell consumer traffic from business or hosting traffic. ASN type labels the network as ISP, BUSINESS or HOSTING, so a consumer provider reads differently from an enterprise or datacenter one. Connection type only ever fills in for home connections, which is a second signal in the same direction - useful when judging whether traffic looks like real users.
How IP-to-ISP lookup works
Every public IP address is allocated by one of the five Regional Internet Registries - ARIN (North America), RIPE NCC (Europe and the Middle East), APNIC (Asia-Pacific), LACNIC (Latin America), and AFRINIC (Africa) - to the organization that operates it. That organization announces the address to the internet under an ASN. An IP to ISP lookup reads this registry and routing data to return the provider and ASN behind the address.
Two limits worth knowing: a VPN or proxy changes the result to the ISP of the exit server, not the user's own connection - so a lookup on VPN traffic shows the VPN provider. And only public IP addresses resolve to an ISP; private ranges (such as 192.168.x.x or 10.x.x.x) exist only inside local networks and have no public provider.
Need to know whether an IP is itself a VPN, proxy, or hosting node? That's a detection question - use the VPN & Proxy IP Detection tool.
FAQs
Use the Find my ISP button to look up your current public IP and the provider behind it. If you're connected through a VPN or proxy, the result will be that service's provider, not your home connection.
VPNs, proxies, and corporate networks route traffic through their own IPs, so the lookup returns their ISP and location. Geolocation is also approximate - it reflects where the network is registered, which may differ from the device's physical location.
IP to ISP headlines the provider name behind an address. IP to ASN lookup headlines the Autonomous System - the ASN number and the network prefixes that organization controls. Both start from an IP and share underlying data; choose IP to ISP when you want the provider, IP to ASN when you want the network detail.