UPDATE December 8, 2018:

Several weeks ago we released an update to our AdBlock for Safari Mac app that (we think) fixed the issue with CPU usage, battery drain, and overheating that many of our users reported to us. Yesterday we released version 1.13.1 and today we followed up with 1.14.0, both of which should help make the app even more stable and lighter on resources. Please make sure you have at least version 1.14.0 (found in AdBlock > About AdBlock). If you have an earlier version, please update AdBlock for Safari in the App Store as soon as possible.

Many of our users are reporting that after they installed our new AdBlock for Safari app, their Macs run hot, their laptop batteries drain faster, and Activity Monitor shows CPU usage at 100%. Our developers are investigating this as a possible bug in either the AdBlock app or Safari.

If you are experiencing this issue, you can help us troubleshoot by opening a ticket at help.getadblock.com. Or, just skip to "Workaround" below.

Please include the following information in your ticket:

  • Your browser and OS version
  • AdBlock's version number, found in AdBlock > About AdBlock
  • The result of the following test:
  1. Open Activity Monitor. Note how the AdBlock app is affecting CPU activity.
  2. Click the AdBlock icon in the MacOS menu bar and deselect (turn off) Start AdBlock at Login.
  3. Quit the AdBlock app.
  4. Note whether there is any difference in CPU activity and if so, how big.

If AdBlock is causing the CPU drain, you should notice a significant drop in CPU usage. If there is no difference, then something other than AdBlock is causing it. It will help us to know either way.

Other information that would be helpful to include in your ticket:

  • Does Activity Monitor show AdBlock's CPU and energy usage climbing steadily over time, or does it spike at certain times, or does it max out as soon as you start Safari with AdBlock set to start at login?
  • Is this happening on all pages you visit or just some (please provide a link to some of those pages)?
  • Does it make a difference if AdBlock is running in the foreground (that is, the app window is visible)?
  • Does it make a difference if you restart your Mac, and if it does, for how long does it make a difference?
  • Does it make a difference if you disable one or both filter lists on the Filter Lists tab in the app window? Which one made the difference?

Thanks for your help!


The CPU and energy drain appear to happen only when the AdBlock app is running. Therefore, the workaround for now is not to run it. Ads will still be blocked as long as the AdBlock Engine extension remains enabled in Safari Extensions Preferences.

Set AdBlock not to run automatically when you start your Mac. If you need to change filter list subscriptions, add or remove whitelist entries, or update the filter lists, run the app and close it when you're done. The only reason to leave the app running is to get filter list updates automatically. The AdBlock extension will open the app if you do something that requires it. Just remember to manually update your filter lists at least every few days.

  1. Click the AdBlock icon in the MacOS menu bar and deselect (turn off) Start AdBlock at Login.
  2. Quit the AdBlock app.