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

3.2 out of 5
139 Ratings

139 Ratings

badkitty_ ,

Works great as long as you remember to enable Safari content blocking!

I thought this wasn't working and that it wasn't removing the dreaded AdChoice ads. I was mistaken! It actually works great as long as you remember to enable Safari Content Blocking in Safari Preferences.

It also respects your privacy! It clearly states it does not have permission to read or transmit content from any webpages. That is definitely not the case with all ad blockers! Some can read your passwords and credit card info and will tell you that (click the fine print next to your Safari extensions in Safari/Preferences/Extensions

Keep up the great work, guys!

Rotors ,

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.

Got blocked ,

Love it ……but , too effective ?

This works as advertised and quietly behind the scenes . Solid ad blocker that just plain works and very effectively .
Unfortunatly its a little too effective . Now I cant log in to access a certain member website that I need access too . I thought the site was just down , but it turns out the KaBlock ad was preventing me to get past the log in screen . Uninstalled KaBlock, and had no problems .
Love this ad Blocker, but sadly cant use it. If it only had a user friendly way to bypass blocking on certain websites that didnt need blocking, it would be perfect .


Negative Code, LLC
3.9 MB

macOS 10.13 or later, 64-bit processor



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.

More By This Developer