Keyboard input lag on macOS 10.14.6 with BTT 3.160

Describe the bug

  1. On macOS 10.14.6, set BTT 3.160 (1333) to launch at startup.
  2. Restart Mac and login.

Result: There is significant keyboard lag/unresponsiveness. I have to press a key several times before it outputs onto the screen, and some keystrokes are simply discarded. (I am using a USB keyboard.)

I had not experienced this behavior prior to updating today to macOS 10.14.6. However, I simultaneously updated to the latest BTT alpha (1333), so I do not know which update (macOS or BTT) is responsible for the behavior. Activity Monitor showed CPU as relatively idle.

Thinking there was perhaps an issue with macOS, I did a complete reinstall of macOS 10.14.6 using the full installer on top of my existing OS (which was already running 10.14.6.). That did not resolve the issue.

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
Keyboard (USB)

If applicable, add screenshots to help explain your problem. (You can just paste or drag them here)

Device information:

  • Type of Mac: iMac17,1
  • macOS version: 10.14.6
  • BetterTouchTool version: (please post the exact version - not just "the latest one") 3.160 (1333)

Additional information (e.g. StackTraces, related issues, screenshots, workarounds, etc.):


  • The keyboard lag ceases once BTT is terminated.
  • The keyboard lag also ceases if BTT is simply restarted; and it doesn't appear that the problem resurfaces until the next login.
  • You can also simply not start BTT at startup and simply launch it after login.

I don't think there is anything in the new BTT that could cause this, however maybe macOS is still busy re-indexing some stuff which can lead to such things.

In such situations the optional priority helper tool can be of great help:

Andreas, the priority helper tool seems to have resolved the issue. I will continue to monitor.

Please keep me updated!
The next few BTT versions will also focus on performance, 3.162 already contains some first improvements.

I spoke too soon. Upon wake from sleep, the issue reoccurred. It happens even when the CPU is over 99% idle.

I have since updated to 3.162 and will continue to monitor.

I have not had a reoccurrence of the keyboard lag since updating to BTT 3.164. I'll continue to monitor.

This issue has not reappeared in the last several versions of BTT. You may close it.