Blog - Using Refract DNS For Ad Blocking

Refract DNS can be used to block ads and trackers as you browse the internet. Helping to keep your privacy and data safe.

How can Refract DNS Help?

Refract DNS contains a bulk blacklisting feature which allows you to quickly and easily block 10,000's of different domains. Currently on my computer I am blocking about 120,000 different domains.

To use this feature you must supply a list of domains to Refract DNS in a specific file format (checkout the documentation for the file format). Luckily for us, we don't need to create this list ourselves. A community of generous individuals have built lists for us that can be freely downloaded from GitHub. When downloading third party lists, you should always check that you trust the source.

The file must be dropped in to the blacklist folder. This is normally located at c:\program files\refract dns\refract dns\data\blacklist, or as a shortcut click on the blacklist number count in Refract DNS to open the folder directly:

Make sure that your file has the correct file extension so that Refract DNS knows which type of list it is handling.

Next, stop and start the Refract DNS service to read the new file. The blacklist files is loaded when the Refract DNS service starts. The service can be stopped and started from the Management Tool by clicking the "Service" toggle on the main screen.

Multiple files can be added to this directory allowing you to use files from multiple different sources.

So how does it work?

When you visit a webpage that has a third party tracking tool that you want to block, for this example let’s say the domain is ''.

The domain '' has been added to our blacklist, either via file or individually via the UI.

When your browser makes a request to Refract DNS for the IP address of the domain '' Refract DNS will respond with the IP address (you can change this but it is the default value), which tells the browser that the domain does not exist and effectively blocks the site and stops the ad or tracker.

There is More!

As well as being able to block ads, using Refract DNS also has these advantages:

  • The blacklist files shared on the internet are designed for use with other tools, for example the Windows Hosts File. If you inspect the file you will see that the file is a combination of domains and IP addresses in a very long list. It is unlikely that anyone downloading these files will check every entry in the file to ensure that it correctly configured to black hole the traffic and not direct it somewhere else. Refract DNS solves this problem by only reading the domain names from the files. When a request for a domain is made Refract DNS will return the IP address configured in the settings of Refract DNS and not from the blacklist file. This makes it much safer for you to use these blacklists and protects you from potential bad entries.
  • The blacklist can be turned on and off with a single button click from within the Refract DNS Management Tool. This is especially useful if you are a web developer who needs to turn off the blacklist to access an advertisers site to integrate it with the project you are working on. Simple turn it off while you perform the integration and then enable it again when you are finished.
  • Refract DNS has no integration with your browser. This means that Refract DNS does not know anything about what is happening inside your browser. This means any content you download or data you enter into a web page is kept private.
  • Refract DNS does not share or report the domains you look at to anyone.
  • Refract DNS does much more than just blacklisting!

Give Refract DNS a go by signing up for a 30 day free trial.

Mike - July 2019


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