The quickest way to find your internet provider is to look up your public IP address: the network that owns it, identified by its ASN, is almost always your ISP. You can confirm it from your router's status page, your bill, the whois command, or the last hops of a traceroute.
Knowing your ISP matters when you report an outage, check whether a problem is local or network-wide, compare plans, or work out why a site blocks you. This guide covers five reliable methods, the cases where they give a confusing answer, and what your ISP can see about your traffic.
Method 1: Look up your public IP address
Every public IP address is allocated to an organisation through a Regional Internet Registry, and announced to the rest of the internet by an autonomous system identified by an ASN. For a home or mobile connection, that organisation is your ISP.
- Open our What Is My ISP tool. It detects your public IP and shows the provider name and ASN.
- For more detail, paste the ASN into the ASN lookup to see the organisation's name, country and announced prefixes.
If ASNs are new to you, our guide What Is an ASN? explains how they fit into internet routing.
When the IP lookup can mislead you
- You are on a VPN or proxy. The lookup shows the VPN provider's hosting network. Disconnect first.
- Your ISP resells another network. Many smaller broadband brands and mobile virtual network operators run over a larger operator's infrastructure, so the lookup shows the wholesale network rather than the brand on your bill.
- You are behind carrier-grade NAT. The provider shown is still correct, but the IP is shared with other customers. See what CGNAT is for details.
- You are on a work or campus network. The result shows the organisation's upstream provider or its own ASN, not your home ISP.
Method 2: Check your router's admin page
Your router talks directly to the ISP, so its status page usually reveals the provider. Sign in to the admin interface, usually at an address such as 192.168.1.1 or 192.168.0.1, and look for a page called Status, Internet or WAN. Useful clues include:
- The WAN IP address and default gateway assigned by the ISP.
- The PPPoE username on DSL and some fibre connections, which often contains the ISP's domain, for example
customer123@isp.example.net. - The DNS servers handed out by the ISP, which you can look up the same way as any IP.
- The router's own branding. If your ISP supplied the router, its logo or firmware name usually gives it away.
Method 3: Your bill or contract
The company that bills you is your retail ISP, even if the lines or the network belong to someone else. If you are a tenant with internet included, ask your landlord or building management, because the building may have a bulk contract with a provider you never signed up with. On a phone, the carrier name in the status bar or under Settings shows your mobile provider.
Method 4: Use the whois command
WHOIS records show who an IP block is registered to. First find your public IP, either from the WhatsMyIPNumber homepage or with a DNS query that returns it:
dig +short myip.opendns.com @resolver1.opendns.comThen query the registry on macOS or Linux:
$ whois 203.0.113.45
inetnum: 203.0.113.0 - 203.0.113.255
netname: EXAMPLE-BROADBAND
descr: Example Broadband residential customers
country: GB
org: ORG-EB1-EXAMPLE
origin: AS64500The exact field names depend on which registry holds the block: ARIN (North America), RIPE NCC (Europe, Middle East, Central Asia), APNIC (Asia-Pacific), LACNIC (Latin America) or AFRINIC (Africa). Look for netname, descr, OrgName or org-name. Windows does not include a whois command, but our WHOIS lookup works for IPs as well as domains.
Method 5: Read the first hops of a traceroute
A traceroute lists each router your packets pass through. The first hop is your own router; the next few belong to your ISP, and their reverse DNS names usually include the ISP's domain.
# Windows
tracert example.com
# macOS / Linux
traceroute example.com
1 192.168.1.1 1.2 ms
2 198.51.100.1 8.4 ms
3 ae2.core1.lon.isp.example.net (198.51.100.34) 9.1 ms
4 be10.edge2.lon.isp.example.net (198.51.100.77) 10.3 msHops 2 to 4 here are inside the ISP's network. If a hop shows only an IP address, run a reverse DNS lookup on it. For more on reading this output, see how to use ping and traceroute.
What your ISP can see about you
Every packet you send passes through your ISP's network, so it is worth knowing what is visible and what is not.
| Information | Visible to your ISP? |
|---|---|
| IP addresses you connect to, ports, timing and data volume | Yes, always, unless you use a VPN or Tor |
| Domain names you look up, if you use the ISP's DNS resolver | Yes. Plain DNS is unencrypted |
| Domain names in the TLS handshake (SNI) | Usually yes, unless the site and browser both support Encrypted Client Hello |
| Full URLs, page content, form data and passwords on HTTPS sites | No |
| Everything on plain HTTP sites | Yes |
How HTTPS, DoH and VPNs change the picture
- HTTPS encrypts the content and the URL path, but the server's IP and usually the hostname (through SNI) remain visible.
- DNS over HTTPS or DNS over TLS hides your lookups from the ISP by encrypting them to a resolver you choose. The ISP can still see the IP addresses you then connect to and, in most cases, the SNI.
- A VPN hides destinations, DNS and SNI from your ISP, which then sees only an encrypted connection to the VPN server and how much data you transfer. The VPN provider gains that visibility instead.
Frequently asked questions
Why does my ISP lookup show a different company than my bill?
Your provider probably uses another operator's network wholesale, or was acquired and still uses the old company's IP registrations. Both are common and do not indicate a problem.
Can a website tell who my ISP is?
Yes. Any site that sees your IP address can look up the ASN and network owner, just as our tool does. It cannot see your account details or name from the IP alone.
How do I find my ISP on a mobile phone?
On mobile data, the carrier name in your phone's settings is your provider, and an IP lookup shows the carrier's network. On Wi-Fi, the lookup shows the ISP of the network you are connected to.
Does my ISP change if my IP address changes?
No. Your ISP assigns addresses from its own pools, so a new IP almost always belongs to the same provider and ASN.