How do ISPs block sites

A lot of ISPs (Internet Service Providers) across the world block websites – some for legitimate reasons, some because of the growing online censorship. In other cases, it’s not the service provider that’s responsible for the blocking.

There are quite a few ways to go about blocking a site. A smaller, niche ISP will probably go with the easier ones that don’t require a lot of resources. Giant providers are usually able to employ methods that can be difficult to bypass. That’s something to keep in mind while you’re picking out an ISP you’ll be happy with – what additional tools will you need to make sure your online experience is the best?

While one can argue that there are sometimes good reasons to block sites, it can ultimately lead to over-restricting and even censorship. People should retain their right to choose the content they want to explore online. In this article, we’ll go over the types of censorship you may come across and how to easily overcome them.

How to check if my Internet Service Provider is blocking any websites?

How to check if my Internet Service Provider is blocking any websites?

A lot of the time, if a website is blocked for you, you will get a generic message that reads something like “this content is not available in your country.” However, that doesn’t necessarily mean that your ISP is blocking that site for you. A lot of websites (or apps) are unavailable in specific countries because their creators or owners chose to do so.

When an ISP is blocking a website, you will likely get an error and not the site you were looking for. You can Google “is it down for everyone or just me” to access free sites that check if the site is actually down. If it is, the error has nothing to do with your provider. If it isn’t, it might have been done on purpose.

If the site seems to be up, but you still cannot access it – even after trying a different browser or device – there’s a chance that your ISP is blocking it. There are ways to bypass that. They depend on the method that your provider is using to deny people access. 

Can your internet service provider see what sites you are on?

Your Internet Service Provider has access to your browsing history, how much time you spend on a website, and what device you’re using.

What can your ISP do with that information?

But the incognito mode protects your privacy, right?

Not really. Going incognito means that the browser isn’t storing your browsing history, login details, and cookies. However, it doesn’t stop ISP tracking.

They don’t hide it, though. When you open the incognito window in Chrome, all this information is clearly articulated:

Incognito in Chrome

To stop your ISP from snooping on your browsing activity, you need a VPN. It’s the most effective way to stop non-consensual online tracking.

What’s DNS blocking & how to bypass it?

DNS (Domain Naming System) blocking or filtering works by preventing your access to a website based on that site’s IP address. Sometimes, it only means a firewall is doing its job properly since this site is known to be malicious and is added to blacklists.

On the other hand, if you’re confident that it’s not your antivirus or firewall protecting you, then it’s your ISP who’s blocking the access. Fortunately, DNS filtering is a straightforward method of blocking sites, and it isn’t hard to get around it. 

You can bypass DNS blocking by either using a VPN or a DNS resolver. A VPN is an overall better solution as it bypasses blocking and filtering while protecting your data from tracking, prying eyes and leaking. 

What’s IP blocking & how to bypass it?

IP address blocking happens when a network is configured to reject access for specific IP addresses. It’s a popular technique to protect sites from brute force attacks or to only allow specific people into a private network. On another side of the coin, it’s often used for online censorship.

It’s possible to either block specific or country-wide IP addresses. While sometimes this method is used for all the right reasons, your ISP may be using IP blocking to prevent your access to legitimate websites. However, with the right tools, it’s easy to bypass IP blocking.

Since bypassing IP blocking requires changing your IP, a DNS resolver cannot help you. Instead, you can download and install a VPN app, connect to a server in a different country, and unlock any content that way.

What’s Deep Packet Inspection & how to bypass it?

Deep Packet Inspection, otherwise known as DPI, is a method that allows examining the data traveling via networks. It’s as if somebody opens a letter you’re sending out and reads what you wrote, which is why DPI does nothing for your privacy.

It’s often used by antivirus programs to detect malicious code or for networking purposes to ensure that data is delivered in the correct format. Of course, it’s also used for spying and online censorship. Since DPI allows such thorough access, it can be easily used for nefarious purposes.

Bypassing Deep Packet Inspection is challenging, to say the least. No DNS resolver can help you, and not all VPN providers are equipped to deal with it. One way to overcome DPI is to use Surfshark. We also recommend turning on Kill Switch. It helps to preserve your privacy in case of any connection drops in such a complicated environment.

How does a VPN unblock sites?

How does a VPN unblock sites?

It first depends on how the website is blocked. In the case of IP blocking, a VPN simply gives you a “fresh” IP that’s not on the blacklist – it’s just as simple as that. If a site is caught up in DNS filtering, a VPN helps you out by resolving DNS on their end (provided they offer private DNS, which Surfshark does).

When it comes to DPI, it’s a little bit more complicated. Bypassing Deep Packet Inspection (which is one of the methods that China uses for its online censorship) is not easy. It requires separate advanced algorithms as well as continuously looking for new techniques that help prevent these invasive tactics.

How does a DNS resolver unblock sites?

You may find that you cannot access specific sites (like Facebook or Twitter) at university, school, or work. In this case, your service provider (which is, for example, your university) receives all DNS addresses automatically, and they are processed via a DNS resolver

For example, Facebook’s IP is If you can remember all the IPs of all the blocked sites, then you’ll get to them just fine. The issue is that those are hard to recall, and you need a DNS resolver to turn to At this point, your provider returns you nxdomain (or worse, their domain) instead of Facebook. 

Here's how DNS resolving works

Your type in the website address and DNS resolves it to the IP address of that site. And vice versa!

With a DNS resolver, these requests are sent to a private server and encrypted with DNS over TLS or DNS over HTTPS, and it’s hard to decipher that those are DNS requests. That’s why your provider can’t overtake and change them – and you can access the blocked sites you want to browse.

Do I need a VPN, or is a DNS resolver enough?

It largely depends on your needs. A DNS resolver will only unblock the sites that are blocked via DNS filtering – and a lot of websites are blocked in different ways. If you simply want to scroll through Facebook at your university, then you’re probably good with a DNS resolver.

However, a VPN does a lot more. First of all, it can unblock way more sites (for example, those that are blocked on IP level or even with the help of Deep Packet Inspection). Another important thing is that a VPN provides you with a much more reliable layer of digital security.

With a VPN, all your traffic is encrypted – not just your DNS requests. It hides everything you do from your ISP (basically, it blocks ISP tracking). Plus, it protects your online activities, and, as a nice bonus, can also unblock a myriad of websites. Plus, you can do things like get cheaper plane tickets and block ads or even malware attempts! So, if you feel like you need more privacy and more entertainment, a VPN is a better fit for your needs. 

When should you use a VPN and a DNS changer?

Use Surfshark VPN to: Use a DNS changer to:
  • Unblock social networks and VoIPs
  • Unblock YouTube or  Wikipedia in all cases
  • Unblock sites if you’re in China or Russia
  • Unblock Facebook, YouTube, Wikipedia, and other sites when they’re blocked via DNS filtering (e.g., at university or work)


Online blocking and censorship may seem daunting, especially if you’re not inclined to learn all the technical details that make blocking and unblocking sites possible. However, thanks to easy-to-use DNS changers and VPNs, you don’t have to get an IT degree to explore the open internet. All it takes is downloading an app for your device, and you’re ready to go.

Bypass ISP blocking with Surfshark VPN

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