How Do Ad Blockers Work & Are They Safe? This Is What You Need to Know

Ad blockers have existed for decades. I often refer to Netscape Browser as being ahead of its time. One reason is that it had the world’s first ad blocker, “Internet Fast Forward,” built for it. Firefox added an extension in 2002. AdBlock Plus, an ad blocker still used by millions, was developed and released in 2006. 

I started with this small history because although I was always aware of ad blockers, I only started using them a couple of years back. Why? Ads on the internet were not as intrusive before as they are today. 

I get between 4 and 6 ads in long-form YouTube videos before and during the video. Facebook has annoyingly long, unskippable video ads. But when I go outside of these mainstream websites, it’s a whole different story. There are hidden ads everywhere. You click on a blank space on a site, and pop-up windows try to load harmful ads from betting and gambling sites to straight-up scams and phishing sites. 

What is an Ad Blocker, and how does it work?

If the name “ad blocker” didn’t give it off already, an ad blocker is an app, extension, DNS, VPN that blocks ads on your web browser, computer, and smartphones. Now different ad blockers work in different ways. but essentially, they utilise some kind of blocklist of different kinds of ads and then blocks it on your device. Lets see how different kinds of ad blockers, block ads.

Browser Extensions

These are the most popular kind. Chances are, if you’re looking for an ad blocker, it is to block ads on a browser. And most browsers have ad blockers in their extension store. Some even come with built-in ad blockers, like Brave. 

These extensions usually require permission to modify scripts on websites. This means when you visit a website, an extension like Total Adblock can see the back-end scripts of that website and identify the ads and tracking scripts. Then, it edits those scripts and ensures you don’t see any ads. 

Apps

App-based ad blockers, like AdGuard, work as a firewall. This allows them to block ads on both web browsers and other apps. So, for example, if you’re sick of in-game ads on Android, you can use this method to get rid of those.

Unlike websites, apps don’t let other apps edit their code to remove ads unless you have root. But we’re not talking about that. So apps like Total Adblock and AdGuard take control of all incoming and outgoing network queries. That way, it can use its blocklist to identify ads and trackers and block them at a system level. 

DNS-based Ad Blockers

DNS-based ad blockers make sure that the ad gets filtered out before it even reaches your network. AdGuard has a DNS offering, but there are also dedicated DNS resolvers like NextDNS that also block ads and enhance privacy. 

A domain name system (DNS) connects the domain names or URLs to their IP addresses. A DNS based ad blocker filters the ads out in that process. So for example, when you add AdGuard as your DNS, it redirects all URLs that show you ads to nowhere. That prevents ads from loading. 

VPN-based Ad Blockers

A VPN or a virtual private network, redirects all your incoming and outgoing traffic through a different network. This hides your IP and allows you to remain anonymous on the internet. You can also get access to region-restricted content by choosing a VPN from a specific country where it is available.

Now VPN-based ad blockers do the same thing, but also blocks ads in the process. As Android and iOS strict restriction for ad blockers on their app stores, a lot of VPN providers like Surfshark and Nord have stepped up to fill that gap. At the same time, ad blockers like Total AdBlock and AdGuard also uses VPN to block ads. 

Host-based Ad Blockers

Host-based ad blockers were very popular in the Android rooting community once. AdAway being the go to option. These ad blockers would utilise root access to change the hosts.txt file in Android system directories to redirect all the queries to nowhere.

Now similar or even better results can be achieved through DNS and VPN-based options. That makes host-based ad blockers obsolete. But if you have a pre-Android 9 device, that does not support private DNS, you can still give this a try.

Are Ad Blockers Safe?

If you have read through this article, you must be wondering, are ad blockers safe? Afterall they are accessing and modifying critical network information and web scripts. They often also control where your data routes through. So that puts them in a powerful position when it comes to your data. But to answer the question, Ad Blockers are safe if you download the right ones from the right sources. 

There are also a lot of open-source ad blockers that allow people to audit their codes, like uBlock Origin, AdGuard, and more. And most blocklists are maintained by communities of dedicated users like you and me. So they are essentially safe. But also be sure to verify where you are getting your ad blockers from. AdGuard and Total Adblock offer their apks on their official website as the full versions are unavailable on the Play Store. So make sure you are sideloading the right one.

Wrapping Up

Ad blockers are incredibly powerful tools that not only improve your browsing experience but also enhance your privacy and security. However, like any tool, their safety depends on where you get them from and how you use them. 

Stick to trusted, well-reviewed options like uBlock Origin, AdGuard, or Total Adblock, and always download them from official sources. If you’re tired of intrusive ads, looking for faster page loads, or want to block hidden trackers, the right ad blocker can make a huge difference, just do your homework and choose wisely. Check out our guide to the best ad blocker to enhance your browsing experience and eliminate intrusive ads.

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