What are Ad blockers and how do they work?

Ki James
Ki James
September 29th, 2021

Nearly a billion users worldwide use Ad blockers when they peruse the internet. These usually come in the form of extensions to the user’s browser of choice, and they remove any advertisements in whatever form they take (pop-ups, video embeds, banners, etc.) That being said, what is Ad blocking, and how do these extensions work?

How it works

There are many basic methods to filter out advertisements, all of which have varying levels of success and complexity. We’re going to look at two different kinds to give you a general idea of the different methods that can be applied to a number of situations.

DNS Filtering

This one is a lot more complicated. Basically, you can imagine a black box that looks at different website URLs and their server hosts, and then prevents the nasty ones from causing you any problems.

This either takes the form of a big “you’re trying to be redirected and we’re preventing that from happening” page from your Ad blocker, or nothing happening at all since the software is handling it behind the scenes.

Stylesheet Formatting

Some advertisements are a lot more clever than others, and are hard coded into the website itself rather than overlaid on top. In these cases, some ad blockers will take all the relevant data, and then overlay it on their own version of the website without any ads.

Reasons to Ad block

While this is all fine and dandy, there are many reasons that some people have for not Ad blocking. These include things like keeping free services on the internet free instead of subscription based, and helping specific sites or creators monetarily.

While these are good natured reasons, there are legitimate privacy concerns when it comes to allowing any ads to appear on your screen at any given time. These include:

  • Protecting your privacy
  • Stopping malvertising (a topic we will most certainly discuss in the near future)
  • Saving bandwidth
  • Saving battery on mobile devices


All in all, Ad blocking can only only take many different, complex forms, but is also important to keeping you safe, your battery nice and full, and your user experience clutter free.

There are many great options you can download today, but Ublock Origin and Adblock Pro are both great places to start.

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