IP, Privacy & Security
What Is an ISP and What Does It Know About You?
Your ISP is your on-ramp to the internet. That privileged position means it can see more about your online life than almost anyone else.
What an ISP does
An Internet Service Provider is the company that connects you to the internet — over cable, fiber, DSL, or a mobile network. It assigns your public IP address, routes your traffic toward its destination, and connects its network to the rest of the internet through peering and transit agreements with other providers.
What your ISP can see
Because all your traffic passes through it, an ISP is uniquely positioned to observe:
- Which sites and services you connect to — at minimum the addresses and, unless you use encrypted DNS, the domain names you look up.
- When and how much — timing and volume of your activity.
- Your assigned IP address and which customer account it belongs to.
Thanks to widespread HTTPS encryption, your ISP generally cannot read the contents of your traffic — the specific pages, messages, or data. But it can often see where you're going.
What they do with it
Practices vary by provider and country. ISPs use traffic data to manage their networks and comply with legal requirements, and some have histories of logging or even selling anonymized browsing data for advertising. Regulations differ widely on what's allowed.
Reducing what your ISP sees
- A VPN encrypts your traffic to its server, so your ISP sees only that you're connected to a VPN, not what you're doing.
- Encrypted DNS (DNS over HTTPS or TLS) hides the domain names you look up from your ISP.
- HTTPS everywhere keeps the contents of your traffic private by default.
The relationship of trust
You can't avoid having an ISP, so it's inherently a party you place trust in. Understanding what it can and can't see helps you make informed choices — and explains why privacy tools focus so much on encrypting the very first hop between you and the wider internet.