What Is My ISP
See which internet service provider your connection belongs to, along with its AS number, from your public IP address.
Detecting your connection…
About What Is My ISP
What Is My ISP identifies the organisation that owns the public IP address your connection is using. When you open the page our EU server sees the source IP of your request, looks it up against a self-hosted IP-to-ASN database, and shows the provider's name and Autonomous System (AS) number. It also reports the IP address itself, its reverse-DNS hostname, and an approximate city, region and country.
Your ISP is the network that assigns you an address and carries your traffic to the rest of the internet. Every such network is registered as an Autonomous System with a unique AS number - for example AS3215 - and the organisation name attached to that number is what identifies your provider. The AS number is more reliable than the friendly name because it is what internet routing actually uses. On a home or office connection the provider shown is your access ISP; on mobile it is your carrier; behind a VPN or proxy it is the provider of whatever exit node you are connected through.
The reverse-DNS hostname - the PTR record for your IP - often hints at your provider and region through naming conventions, though not every address has one. The location is derived from an IP geolocation database and is approximate: it typically resolves to your provider's regional point of presence rather than to your street address.
The lookup uses the self-hosted DB-IP Lite databases on our own EU servers, so your IP address is not sent to any third-party geolocation API, and we do not log or store it. Only the public IP visible to any server you connect to is used - nothing is read from your device beyond the request your browser already sends.
How to use it
- 1Open the tool - it automatically detects the public IP address your request arrives from.
- 2Read the provider name and AS number shown as the headline result.
- 3Review the supporting details: your IP address, reverse-DNS hostname and approximate location.
- 4Compare the result with and without a VPN to see which provider each path exposes.
Common use cases
- -Confirming which ISP or carrier a connection is actually using, at home, in the office or on mobile.
- -Checking whether a VPN or proxy is active by seeing which provider and AS number the internet sees.
- -Finding the AS number of your network for peering, abuse reports or firewall allow-lists.
- -Verifying that traffic exits through the expected provider after a network or routing change.
Frequently asked questions
- How do I find out who my ISP is?
- Open this tool and it reads the public IP address your connection is using, then looks up the owning organisation and its AS number. The provider shown is whoever operates the network your traffic exits through.
- What is an AS number?
- An Autonomous System (AS) number is a unique identifier for a network on the internet, such as AS3215. Every ISP operates one or more autonomous systems, and the AS number is the most reliable way to identify the provider behind an IP address.
- Why does my ISP show a different company than the one I pay?
- The tool shows the operator of the network your traffic actually transits, which may be a parent company, a wholesale carrier, or - if you use a VPN or proxy - the provider of your exit node rather than your retail ISP.
- Does this tool store my IP address?
- No. The ISP and location lookup runs against self-hosted databases on our EU servers, and your IP address is not logged, stored, or sent to any third-party service.
- How accurate is the ISP and location result?
- The ISP name and AS number come from an IP-to-ASN database and are generally accurate to the operating network. The location is approximate and usually points to your provider's regional point of presence, not your exact address.