ISP

What is an ISP?

An Internet service provider (ISP) can provide home or work access to the Web, along with things like domain name registration and Web hosting. For many home Internet users, being online means all data must go through some sort of ISP (and this ISP can see all your traffic and online activity unless you take steps to prevent it). Some examples of ISPs include Comcast, AT&T, and Verizon.

Which companies are ISPs?

Any company that brings you home Internet service is an ISP. Major home ISPs in the United States are Comcast (branded as Xfinity), Spectrum, and Verizon. They also offer service to commercial customers like office buildings, cafes, airports, and so on. ISPs often offer cable TV service in addition to Internet service, because TV and Internet service usually (though not always) use the same infrastructure.

Cellular carriers are also ISPs, offering Internet access to smartphone and tablet users. In the United States, major ISPs in this category include AT&T, Sprint, T-Mobile, and Verizon.

How do I choose an ISP?

For home or business Internet, the available ISPs will vary by region. Those ISPs are often local monopolies, like electric utilities, so you may not have a choice at all.

However, even if you don’t have a choice of ISP, you may be able to choose among several service plans. When evaluating ISPs or service plans, you can consider factors like price, speed, and data caps (the amount of data you’re allowed to use in a given time span, usually measured monthly). Generally, you can pay higher prices in exchange for faster speeds and more generous data caps.

For cell service, in addition to price, speed, and data caps, you’ll want to consider geographic coverage. The quality of a carrier’s coverage can vary quite a bit, especially outside major cities. In general, the greater the coverage, the less likely you are to hit “dead zones” (spots where you’re without a cell signal because the provider doesn’t have a tower nearby.)

What are the privacy concerns around ISPs?

All of your Internet traffic flows through your ISP, so your ISP can see which servers you’re connecting to. That tells them what sites you’re browsing, but as long as you’re using HTTPS, they can’t see what you’re doing there. For example, they might see that you’re using Facebook, but they wouldn’t be able to see what you’re posting or which profiles you’re looking at.

Depending on what country you’re in, the ISP may be allowed to sell information about your Internet activity.

ISPs can also see if you’re using video chat or streaming services, and depending on the country, they may be allowed to treat this traffic differently, such as by slowing it down, prioritizing it lower than other types of traffic, or subjecting it to different pricing or data caps. This can let them save infrastructure costs, or raise revenue by charging customers to avoid this treatment. This gets into the network neutrality (net neutrality) debate, and is an example of the risks of concentrating power in ISPs.

Can a VPN keep my data private from an ISP?

Using a VPN can mitigate what an ISP can know about you, and also its ability to prioritize one person’s traffic over another. When you’re connected to a VPN, your ISP will only be able to see that your traffic is going to a VPN provider, but they won’t know anything else about it. However, the VPN provider can see which sites you’re browsing, and what other services you’re using. By using a VPN, you’re placing your trust in the VPN provider instead of the ISP.