An ISP (Internet Service Provider) is a company or organization that provides access to the internet. It delivers connectivity through various technologies — such as fiber-optic cables, DSL (Digital Subscriber Line), satellite, cellular networks, or wireless broadband. You can instantly check who is my ISP using our ISP lookup tool.
Every time you connect to the internet — whether from home, a café, or your smartphone — you're connected through an ISP. To identify which provider you're using, you can easily check using Who is my ISP. You can also view detailed information about my IP address and learn more about IP addresses.
An ISP does far more than just give you internet access. It forms the backbone of your online connectivity:
Related Entities: Internet backbone, IPv4, IPv6, DNS, IXP, DDoS mitigation, routing protocols (BGP, OSPF)
ISPs can be classified based on infrastructure ownership, scale, and service type.
Tier 1 ISPs operate global backbone infrastructure and have direct peering agreements with other Tier 1 providers (no transit fees).
Examples: AT&T, Verizon, Lumen Technologies (CenturyLink), NTT Communications, Telia Carrier
Entities: Internet backbone, global routing, AS numbers, BGP peers
Regional or national providers that buy transit from Tier 1 ISPs but peer locally. Commonly serve businesses and ISPs in specific regions.
Examples: Comcast Business, Cox Communications, Charter Spectrum, British Telecom (BT)
Entities: Regional ISP, upstream providers, peering exchanges
Provide internet directly to end users (residential and small business). Purchase bandwidth from Tier 2 or Tier 1 ISPs.
Examples: Xfinity, Spectrum, Verizon Fios, Frontier, T-Mobile Home Internet
Entities: Last-mile delivery, residential broadband, cable modem, FTTH
Offer cellular data connectivity via 4G LTE, 5G, and satellite networks.
Examples: T-Mobile, AT&T, Verizon Wireless, Mint Mobile, Visible, Google Fi
Entities: 5G NR, LTE, mobile core network, eSIM, MVNO
Provide internet access to rural or remote regions via orbiting satellites.
Examples: Starlink (SpaceX), HughesNet, Viasat
Entities: LEO (Low Earth Orbit), Ka-band, geostationary orbit, SpaceX, ground stations
Use radio frequencies (RF) and microwave transmission for fixed wireless broadband.
Entities: Point-to-point (P2P), line-of-sight (LOS), wireless bridge, antenna sectors
Provide dedicated servers, VPS hosting, colocation, and data center connectivity.
Examples: MonoVM, 1Gbits, DigitalOcean, OVH, Hetzner, Linode, Vultr
Entities: Data center, KVM, hypervisor, ASN registration, bandwidth provider
Here's a quick overview of the most prominent ISPs serving U.S. households and businesses:
| ISP Name | Type | Primary Technology | Coverage Area |
|---|---|---|---|
| Comcast Xfinity | Tier 3 (Retail) | Cable / Fiber | 39 states |
| AT&T Internet / Fiber | Tier 1 + Mobile | Fiber / DSL / 5G | 21 states |
| Spectrum (Charter) | Tier 2 | Cable / Fiber | 41 states |
| Verizon Fios | Tier 1 + Retail | Fiber / 5G | East Coast |
| T-Mobile Home Internet | Mobile ISP | 5G / LTE | Nationwide |
| Starlink (SpaceX) | Satellite ISP | LEO Satellite | Nationwide |
| Frontier Communications | Tier 3 | Fiber / DSL | 25 states |
| Cox Communications | Tier 2 | Cable | 18 states |
Entities: broadband coverage, FCC, fiber-to-the-home (FTTH), DOCSIS, LEO constellations
ISPs form the digital backbone of modern society. They not only connect billions of people but also power:
Choosing a reliable ISP ensures faster speeds, lower latency, and consistent uptime.
ISP stands for Internet Service Provider — a company that supplies users with internet connectivity through wired or wireless means.
Use Who is my ISP. It automatically detects your provider, IP address, and connection type without requiring any installation.
A mobile ISP offers data connectivity via cellular networks (4G LTE, 5G). Examples: T-Mobile, Verizon Wireless, AT&T Mobility.
A satellite ISP uses orbiting satellites to deliver data, ideal for remote areas. Fiber and cable ISPs use underground cables, offering higher bandwidth and lower latency.
Based on average speed test data:
ISPs use DNS servers to resolve domain names into IP addresses. Changing DNS (e.g., to Cloudflare DNS 1.1.1.1) can sometimes improve speed and privacy.
Yes. You can:
An Internet Service Provider (ISP) is your gateway to the digital world, powering everything from web browsing to video streaming. Whether it's a fiber giant like AT&T, a satellite innovator like Starlink, or a wireless carrier like T-Mobile, understanding how ISPs work helps you choose smarter — and troubleshoot faster.
Before any speed test or network optimization, start by discovering your current ISP using Who is my ISP.
Want to know who provides your internet? Use our free tool to instantly identify your ISP, IP address, and connection details.