An ISP (Internet Service Provider) is the company that gives you access to the internet β whether through a broadband cable, fibre, DSL line, or mobile data connection. Every device that connects to the internet does so through an ISP. You can see your current ISP and ASN on whatsmy.fyi.
What Does an ISP Do?
An ISP operates the physical and logical infrastructure that connects your home or business to the global internet. This includes:
- Providing the physical connection (cable, fibre, DSL, 4G/5G)
- Assigning you a public IP address (static or dynamic)
- Routing your traffic to and from the internet via interconnects with other ISPs and internet exchange points (IXPs)
- Offering DNS resolution services
- In some countries, logging traffic metadata as required by law
What Is an ASN?
An Autonomous System Number (ASN) is a unique identifier assigned to a network that operates its own routing policy on the internet. Every ISP, large organisation, cloud provider, and CDN operates one or more autonomous systems (ASes) identified by their ASN.
ASNs are 16-bit or 32-bit numbers, written as AS followed by the number (e.g., AS15169 is Google, AS32934 is Meta, AS9121 is TΓΌrk Telekomunikasyon). When you connect to the internet, your traffic flows through your ISP's autonomous system.
ASNs are publicly registered, which is why websites can identify your ISP by your IP address. The IP address block you are using is announced by your ISP's ASN in global BGP (Border Gateway Protocol) routing tables β public records that anyone can query.
Types of ISPs
- Tier 1 ISPs: The backbone of the internet. They do not pay anyone to reach any destination on the internet and interconnect with each other for free (peering). Examples: AT&T, Deutsche Telekom, Telia.
- Tier 2 ISPs: Regional ISPs that peer with some networks for free and pay Tier 1 ISPs for global reach. Most national ISPs fall here.
- Tier 3 ISPs: Local ISPs that only purchase internet transit from Tier 1 or Tier 2 ISPs. Many small regional broadband providers are Tier 3.
- Mobile ISPs: Mobile network operators (Verizon, Vodafone, etc.) that provide internet access via cellular networks.
What Can Your ISP See?
Your ISP sits between your device and the internet, so it has significant visibility into your traffic:
- Which domains you visit: Even with HTTPS, your ISP can see the domain names you connect to (via DNS queries and SNI in TLS handshakes).
- Volume and timing: How much data you send and receive, and when.
- IP addresses: The servers you connect to.
- Not the content: With HTTPS (which virtually all sites use today), your ISP cannot read the actual content of your communications.
Using a VPN encrypts all your traffic before it reaches your ISP, preventing them from seeing even the domain names you visit. However, they can still see that you are connected to a VPN server.
ISP vs VPN: What Is the Difference?
If you connect to the internet through a VPN, websites see the VPN provider's IP address and ASN instead of your ISP's. whatsmy.fyi's VPN detection checks whether your current ASN belongs to a known VPN provider. If you see a VPN provider name in the ISP field instead of your home broadband company, your VPN is working correctly.
Frequently Asked Questions
How do I find out who my ISP is?
The fastest way is to visit whatsmy.fyi β it shows your ISP name and ASN instantly, without any login or registration.
Does using HTTPS protect me from my ISP?
HTTPS protects the content of your communications. Your ISP can still see which domains you connect to (via DNS and SNI), but not what you read or submit. For full traffic privacy from your ISP, use a VPN or Tor.
Can I change my ISP?
Yes. In most countries, you can switch between competing ISPs. In rural areas, choice may be limited to one or two providers. Satellite ISPs like Starlink are expanding options in areas with limited wired infrastructure.
