Ka-Block! is a content blocker for Safari that prevents ads and tracking scripts from slowing down web pages you visit.

Many sites use third-party scripts to track your behavior across the web, causing pages to load slowly and draining your Mac’s battery. Blocking these scripts dramatically improves page load time, data usage, and battery life.

- Fast, curated filter list
- Open source
- Also available for Safari on iPhone

Protecting privacy and performance on the web is important. We hope you enjoy Ka-Block!

What's New

Version 3.2

Updates to the filter list.

Ratings and Reviews

3.6 out of 5

50 Ratings

50 Ratings

Beware: only installs in Safari


Safari Technology Preview is set as my default browser, but when I tried to add Ka-Block to STP 50, it loaded in Safari instead. I previously reported a bug stating that STP takes me to the new Safari Extensions on the Mac App Store, someone at Apple wrote back that is the expected functionality. I couldn’t wait to try it! When I clicked “Get," Safari was closed. Since I didn’t see it in STP, I checked Safari and there it was. Now, there doesn’t seem to be a way to install Ka-Block into STP. The basic Safari Extensions web page now directs me to the Mac App Store. I wish the Mac App Store stated "Safari only" on each extension.

Ignore the uninstall whiners...

8 bit snow

So far, this is a decent and no fuss blocker. Yes, it lacks customization, but if that is your thing…. You have plenty of other options! And to uninstall…. 1.) delete the app like you would any other app. 2.) quit safari (could do this as step 1 - doesn’t matter). 3.) open safari again and you’ll see that it is gone from the extensions! It can’t get any more simple save for a big “I AM AN IDIOT AND NEED THIS GIANT UNINSTALL BUTTON”. The app makes no promises of being configurable, so if you dinged the dev on that issue…. I give you 1 star for reading comprehension.

Made Safari faster and stopped adware


I think those whining about this App are those who run websites that are abusing Safari.
Ka works great , I was using Yahoo with Safari and it would change pages by itself ,
my anti virus software stopped the webpages from opening because of malicious content
but Ka stopped the browser from doing so.
Anti Virus is not enough, Ka completes the job. It has made my browser faster as well.


Negative Code, LLC
3.9 MB
Age Rating
Rated 4+
© 2015-2018 David Graham & Josh Peek


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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