What Is an ISP (Internet Service Provider)?
An ISP (Internet Service Provider) is the company that provides your internet connection. When you pay for home or mobile internet, you're paying an ISP to connect your devices to the global internet infrastructure. Common ISPs include Comcast Xfinity, AT&T, Verizon, Spectrum, and T-Mobile in the United States, or BT, Sky, and Virgin Media in the United Kingdom.
Every device connected to the internet receives a public IP address assigned by the ISP. This IP address identifies your connection on the internet and can reveal information about your provider, approximate location, and network routing. Our free ISP checker uses your public IP to instantly detect who your Internet Service Provider is, along with your ASN, organization, and geographic details.
Whether you want to find out who your ISP is, verify your VPN is working, or check your IPv4 and IPv6 connectivity, this tool provides instant results with no input required. The detection happens automatically when you load the page, using multiple data sources including IP geolocation databases and internet registry records.
How the ISP Detection Tool Works
Our ISP lookup tool identifies your Internet Service Provider through a simple four-step process that completes in under a second:
Detect Your IP
When you visit this page, your browser connects to our server. We read your public IP address from the connection headers, detecting both IPv4 and IPv6 addresses when available.
Query IP Databases
Your IP address is looked up against IPinfo and other geolocation databases. These databases map IP ranges to their registered owners — the ISPs and organizations that control them.
Resolve ISP Details
The database returns your ISP name, organization, Autonomous System Number (ASN), hostname, and geographic data including city, region, country, timezone, and coordinates.
Display Results
All detected information is displayed instantly. IPv4 and IPv6 addresses are shown separately with copy buttons. Use the Refresh button to re-detect if your connection changes.
Understanding Your ISP Information
When you check your ISP with our tool, the following information is detected from your public IP address:
ISP Name
The name of your Internet Service Provider — the company that provides your internet connection (e.g., Comcast, AT&T, Vodafone, BT).
IPv4 Address
Your 32-bit public IP address in dotted-decimal format (e.g., 203.0.113.42). This is the address most websites and services see when you connect.
IPv6 Address
Your 128-bit IPv6 address if your ISP supports dual-stack networking (e.g., 2001:db8::1). Not all ISPs have deployed IPv6 yet.
ASN
Autonomous System Number — a unique identifier for your ISP's network in the global routing table (e.g., AS15169 for Google, AS7922 for Comcast).
Organization
The registered organization name for the IP range. This may differ from the ISP consumer brand name (e.g., 'Comcast Cable Communications' vs 'Xfinity').
Location
Approximate geographic location based on IP geolocation databases. Shows city, region/state, and country. Accuracy varies by ISP and region.
IPv4 vs IPv6: Understanding Your IP Addresses
Our ISP checker detects both IPv4 and IPv6 addresses when available. Understanding the difference between these two protocols is important for network troubleshooting and connectivity testing.
IPv4 (Internet Protocol v4)
- 32-bit addresses (e.g., 192.168.1.1)
- ~4.3 billion unique addresses
- Universally supported by all ISPs
- Address pool nearly exhausted
- Uses NAT for address sharing
IPv6 (Internet Protocol v6)
- 128-bit addresses (e.g., 2001:db8::1)
- 340 undecillion unique addresses
- Built-in IPsec security
- No NAT needed — end-to-end connectivity
- Not yet supported by all ISPs
If our tool detects both IPv4 and IPv6, your ISP supports dual-stack networking — the recommended configuration for modern internet connectivity. If only IPv4 is detected, your ISP has not yet deployed IPv6 on your connection. Use our DNS Lookup tool to check if a domain has both A (IPv4) and AAAA (IPv6) records.
What Your ISP Can See About Your Internet Activity
Your ISP acts as the gateway between your devices and the internet. This position gives your ISP potential visibility into certain aspects of your online activity. Understanding what your ISP can and cannot see helps you make informed decisions about your privacy.
What Your ISP Can See
- Domain names you visit (e.g., example.com)
- When you are online and for how long
- Total data usage (upload/download volumes)
- IP addresses of servers you connect to
- Unencrypted DNS queries (if not using DoH/DoT)
What Your ISP Cannot See (with HTTPS)
- Specific pages you view on HTTPS sites
- Content of web pages and downloads
- Login credentials and passwords
- Messages, emails, or form submissions
- Any data when using a VPN tunnel
To minimize ISP visibility, use HTTPS websites (check with our SSL Checker), enable DNS-over-HTTPS (DoH) in your browser, and consider using a VPN for complete traffic encryption. You can verify your VPN is working by checking if this ISP tool shows the VPN provider's information instead of your real ISP.
VPN, Proxy & Tor: How They Affect ISP Detection
If you are using a VPN, proxy, or Tor browser, the ISP information shown on this page will reflect the exit server rather than your actual ISP. This is expected behavior and confirms that your privacy tool is working correctly.
VPN Connected
Shows VPN provider's ISP name and server location. Both IPv4 and IPv6 should change. If IPv6 still shows your real address, you have an IPv6 leak.
Proxy Server
Shows the proxy server's ISP and location. Only HTTP/HTTPS traffic is proxied — DNS queries may still go through your real ISP (DNS leak).
Tor Browser
Shows the Tor exit node's ISP and location. The exit node changes periodically, so refreshing may show different ISPs and locations.
Types of Internet Service Providers
ISPs deliver internet access through various technologies, each with different speed, latency, and availability characteristics:
Fiber Optic
Fastest available. Uses light signals through glass fibers. Available in urban and suburban areas.
Cable
Uses coaxial cable TV infrastructure. Widely available. Speeds may decrease during peak hours (shared bandwidth).
DSL
Uses telephone lines. Available almost everywhere. Speed decreases with distance from the ISP's central office.
Satellite
Available everywhere. High latency due to signal travel to orbit. LEO satellites (Starlink) offer 20-40ms latency.
Fixed Wireless
Uses radio signals from a nearby tower. Growing in rural areas. Requires line of sight to the tower.
Cellular (4G/5G)
Mobile internet via cell towers. 5G offers fiber-like speeds in covered areas. Shared bandwidth per tower.
Your ISP type affects your connection quality. Use our Ping tool to measure your actual latency, or run a Traceroute to see the network path between you and any server.
Related Network & DNS Tools
Complement your ISP check with these free network diagnostic and DNS tools:
Look up detailed information for any IP address — geolocation, ISP, ASN, and organization.
Test network latency and connectivity to any host with ICMP ping.
Trace the network path between your ISP and any destination server hop by hop.
Check all DNS records (A, AAAA, CNAME, MX, NS, TXT) for any domain.
Verify SSL certificate validity, expiration, and security configuration.
Check if specific ports are open or closed on any server or IP address.
Test email server connectivity and SMTP configuration on ports 25, 465, 587.
Analyze HTTP response headers and security header configuration.
Frequently Asked Questions About ISP Detection
What is my ISP?
Your ISP (Internet Service Provider) is the company that provides your internet connection. This page auto-detects your ISP name from your public IP address. Common ISPs include Comcast, AT&T, Verizon, Spectrum, T-Mobile, BT, Sky, and Vodafone.
Who is my ISP and how do I find out?
Simply visit this page — your ISP is automatically detected from your public IP address. The tool shows your ISP name, organization, ASN, IP address, and location. You can also check your internet bill or router settings to find your ISP.
What does ISP stand for?
ISP stands for Internet Service Provider — the company that provides internet access to your home or business through fiber, cable, DSL, satellite, or cellular networks.
Can my ISP see what I do online?
Your ISP can see domain names you visit and when you're online, but HTTPS encryption (used by most sites) hides specific page content. Use a VPN to encrypt all traffic and prevent ISP monitoring.
Why does my ISP show a different location?
IP geolocation is approximate and shows your ISP's regional hub, not your exact address. City-level accuracy is 50-80%, while country accuracy is over 99%. VPN users will see the VPN server's location.
What is an ASN (Autonomous System Number)?
An ASN is a unique number assigned to networks on the internet. ISPs, cloud providers, and large organizations each have ASNs used for BGP routing. For example, Google is AS15169 and Cloudflare is AS13335.
How do I check if my VPN is working?
Use this ISP checker with and without your VPN. With VPN active, you should see the VPN provider's ISP name and server location. Check both IPv4 and IPv6 — some VPNs leak IPv6 traffic.
What is the difference between IPv4 and IPv6?
IPv4 uses 32-bit addresses (4.3 billion total), while IPv6 uses 128-bit addresses (virtually unlimited). Our tool detects both. If only IPv4 appears, your ISP hasn't deployed IPv6 on your connection yet.
Can I change my ISP or IP address?
You can change your ISP by switching providers. To change your IP, restart your router (dynamic IP), use a VPN, or use a proxy. Most residential ISPs assign dynamic IPs that change periodically.
Is this ISP checker free and safe?
Yes, it's 100% free with no registration. We only read your public IP (visible to every website you visit) and look up ISP information. We don't store or share your data.