RadBlock Blog

Introducing RadBlock

RadBlock is a blocker for Safari which is unintrusive, fast, and efficient.

Rather than striving for blocking perfection, its main focus is to preserve your battery life by using less resources, and to blend in with the Mac’s native ecosystem.

Why Safari?

Safari, out of the box, delivers the best browsing experience on the Mac for users. It integrates deeply with macOS and iOS, which means that it outshines others in terms of its ease of use1, rendering speed, and efficiency. These factors play a huge role in preserving your device’s battery life.

Other browsers are often favored by developers, and are consequently regarded as better, because Safari sometimes takes a little longer to adopt new web technologies. We believe, however, that Safari evolves at a different pace in order to give high priority to protecting the user’s best interests in terms of experience and privacy.

We think that’s pretty neat!

Existing blockers for Safari

Safari requires its extensions to be written, signed, and notarized by developers in Apple’s paid developer program. Here’s the catch: these extensions must be embedded within native applications, which are written in Apple-native languages that are quite different from those used for the web. This has resulted in blockers being written by people without a lot of experience targeting Apple’s platforms.

As a result, we’ve found existing blockers to be at odds with Safari’s raison d’être: they’re bloated, inefficient, and/or poorly designed. If an extension causes Safari to slow down, use more power, or require an extension’s app to be running, it becomes a total bummer — especially if that app is pissing your battery’s life away.

A new blocker

Our blocker – RadBlock – works just as you’d expect, using rules maintained by the most popular blocking community in the world2.

With your consent, its blocking rules are updated automatically as you use Safari without any interaction or visual distractions. The rules are pre-compiled and distributed to your Mac using iCloud3, meaning it will never “phone home” and your Mac doesn’t have to waste any energy to adapt to websites as they evolve. It’s 10x to 200x more efficient4 than the other blockers we’ve tested, including those of which have their own “cloud” rules.

RadBlock works by using Safari’s official blocking technology, which means that it doesn’t have access to the contents of webpages that you visit. While this may, at times, result in some inaccuracies, we’ve found this to be a reasonable trade-off: your data remains private5 and your Mac’s resources remain free.

Lastly, RadBlock doesn’t try to be something that it’s not: an application. Once you’ve set it up, you never have to open it again. From Safari, you can access RadBlock’s preferences window, which matches Safari’s aesthetic. The RadBlock experience is one that feels like it was built and shipped with Safari.

We’re looking for testers!

Before its release in the Mac App Store, we thought it’d be best to run a private beta to make sure it works as well for you as it does for us.

To join our waiting list, simply follow @RadBlockApp on Twitter. While we’re in beta, we’re keeping our account protected, but we’ll approve your request whenever we can based on time/capacity.

We can’t wait to get RadBlock in your hands… hang tight! 🤙


  1. Safari’s “ease of use” complements its integration with Apple’s operating systems and services. For example, if you save your password in Safari, you can access it seamlessly from iOS without needing to install anything, for free. ↩︎︎
  2. We proudly use EasyList derivatives that we custom tailor to be more easily configured within our app. ↩︎︎
  3. iCloud is unavailable outside of the Mac App Store, so we have to use our own servers (without exchanging information) in the beta version. See our Privacy Policy for more information. ↩︎︎
  4. Our tests were performed using the latest version of 1Blocker, AdGuard and AdBlock on macOS Catalina. We updated the same rule sets 5 times and observed the difference between the “CPU Time” in Activity Monitor.app. ↩︎︎
  5. Some blockers (e.g. AdGuard) use custom code to block content, which means that scripts are injected into every site you visit. These scripts naïvely evaluate code, downloaded from the internet, to figure out what should be blocked. What if a rule was compromised to inject code which steals your data? ↩︎︎