How to Find Your ISP — Check Your Internet Provider

What Is an ISP?

An ISP is any company that sells you network transit — the ability to exchange packets with the rest of the internet. Residential ISPs like Comcast, BT, or Jio sell you connectivity over coax, fiber, DSL, or wireless. Mobile carriers like Verizon Wireless or T-Mobile act as your ISP whenever you’re on cellular data. Enterprise customers buy from tier-1 backbones like Lumen, Cogent, or Tata Communications.

When a website, game server, or API sees your IP, it can look up which organization owns that IP address — and the owner is (usually) the ISP whose network your packets are leaving from. That lookup is what powers “find my ISP” tools.

How IP-to-ISP Lookup Works

Every public IP address on the internet is officially assigned to an organization. Two public data sources let anyone resolve an IP to its owner: WHOIS and BGP ASN lookups.

WHOIS Lookup

The five Regional Internet Registries (RIRs) allocate blocks of IPs and maintain public WHOIS databases of who owns what:

• ARIN — North America
• RIPE NCC — Europe, Middle East, Central Asia
• APNIC — Asia Pacific
• LACNIC — Latin America and Caribbean
• AFRINIC — Africa

Query any RIR’s WHOIS server with an IP and you get fields like NetName, OrgName, Country, NetRange, and contact emails. The OrgName is usually the ISP name. For example, WHOIS of 24.201.64.1 returns Videotron; 86.25.0.1 returns BT Public Internet Service; 124.123.0.1 returns Tata Teleservices.

BGP ASN Lookup

ASN stands for Autonomous System Number. Every major network on the public internet has one — it’s the identifier used by the BGP routing protocol that actually moves packets between networks. Each ASN maps to an organization, and each IP block is announced (“originated”) by at least one ASN.

Well-known residential ISP ASNs: AS7922 Comcast, AS7018 AT&T, AS22773 Cox Communications, AS20115 Charter/Spectrum, AS2856 BT, AS9498 Bharti Airtel, AS55836 Reliance Jio. You can query ASN databases like bgp.he.net or MaxMind to resolve an IP to its announcing ASN and organization.

Services That Wrap All This Up

You don’t have to run WHOIS commands yourself. Our What Is My IP tool returns your ISP automatically. Other services that do the same include ipinfo.io, whatismyisp.com, MaxMind’s GeoIP2 ISP database, and the ARIN WHOIS web interface at whois.arin.net. Paid databases have more accurate ISP-vs-hosting classification than free ones.

Why ISP Detection Can Be Wrong

The ISP name you see is the owner of the IP you’re connecting from — which isn’t always the company you pay a monthly bill to.

VPN and Proxy Users

If you’re on a VPN, the IP belongs to the VPN provider, not your home ISP. You’ll see names like NordVPN, Mullvad, Proton, or the hosting provider they lease from (DigitalOcean, OVH, Amazon). See our guide to hiding your IP for why that’s intentional.

Corporate and Campus Networks

Office and university networks typically use a business-class ISP or even multi-homed transit. You might see the corporate parent’s name, a regional backbone provider, or a hosted-IP block registered to the enterprise itself — not the company you’d think of as “internet provider.”

Mobile Carriers

On cellular, the IP is owned by the mobile carrier’s core network. The name matches your carrier (Verizon Wireless, T-Mobile, Vodafone IN) but the geographic location is often the carrier’s aggregation center rather than where you’re physically standing.

Cloud and Datacenter IPs

Traffic routed through AWS, Google Cloud, Azure, Cloudflare, or Fastly shows those companies as the “ISP,” even though no human is “buying internet” from them. Any service accessed through a cloud-hosted reverse proxy (which is increasingly common) will make you look like you’re “on Cloudflare” when you’re really on your home ISP.

CGNAT and Reseller ISPs

Small regional ISPs often lease upstream bandwidth from a larger provider, and in some cases the IP block is registered to the upstream. With CGNAT (Carrier-Grade NAT), your public IP is shared with hundreds of other customers, and the visible owner might be a tier-2 backbone rather than the branded retail ISP you pay.

Major Residential ISPs in 2026

If you want to recognize common ISP names when they appear:

• North America: Comcast/Xfinity, AT&T, Verizon Fios, Spectrum/Charter, Cox, Bell, Rogers, Videotron, Telus
• UK & Ireland: BT, Sky Broadband, Virgin Media, TalkTalk, Vodafone, EE, Eir
• Europe: Deutsche Telekom, Vodafone DE, Orange, Free/Iliad, Telefónica/Movistar, TIM, KPN, Proximus
• India: Reliance Jio, Bharti Airtel, BSNL, ACT Fibernet, Tata Play Fiber
• East Asia: NTT, KDDI, SoftBank (JP); SK Broadband, KT, LG U+ (KR); China Telecom, China Unicom, China Mobile (CN)
• Australia & NZ: Telstra, TPG, Optus, Aussie Broadband, Spark, Vodafone NZ

What Your ISP Can See About You

Since your ISP routes all your packets, they see the destination of every connection. Even with HTTPS encrypting the content, they see the hostname via the SNI field (the public name of the server you’re connecting to) and the IP/port. Unless you use encrypted DNS (DoH/DoT), they also see every domain your browser looks up. Traffic volumes, timing, and connection patterns are visible.

They don’t see the content of HTTPS-encrypted pages, search queries you submit via HTTPS, or messages in end-to-end encrypted apps. Retention of this metadata varies by jurisdiction — in the EU, data retention laws have been rolled back repeatedly; in the US, ISPs can legally sell browsing metadata to advertisers.

Tier 1, Tier 2, and Tier 3 ISPs

Not every ISP connects directly to the rest of the Internet. Providers sit in a three-level hierarchy that determines how traffic actually reaches the wider world, and this is the reason an IP-to-ISP lookup sometimes returns a company you’ve never heard of.

Tier 1: the backbone

A Tier-1 ISP can reach every other network on the public Internet without paying for transit, through settlement-free peering agreements. There are roughly 15 Tier-1 networks worldwide, including Lumen (formerly CenturyLink/Level 3), Tata Communications, Telia Carrier, NTT, and GTT. You don’t buy service from them as a consumer; they sell bandwidth to other ISPs.

Tier 2: the regional carriers

Tier-2 ISPs peer with some networks for free but pay a Tier-1 for transit to reach the rest. This is where most big consumer ISPs actually sit: Comcast, AT&T, Verizon FiOS, BT, Jio, Telstra. When a WHOIS lookup names “Cogent” or “Hurricane Electric” for your IP but your bill says “Comcast”, you’re seeing a Tier-1 or Tier-2 upstream that Comcast routes through for certain destinations.

Tier 3: the last-mile resellers

Tier-3 ISPs buy all their transit from upstream providers. Rural WISPs, small-town cable co-ops, and white-label broadband resellers fall here. The retail brand on your bill may resolve via WHOIS to whichever Tier-2 actually owns the IP block. That’s why switching to a smaller local ISP sometimes shows the WHOIS name of the regional backbone instead.