I just upgraded to OS X 10.11.2 (El Cap), and overall it seems to be working OK.

One strange thing: there's a "pkd" process which is taking ~150% CPU, all the time, even though I'm not doing anything.

(At first I thought it might have something to do with Spotlight reindexing or something, but 12 hours later it's still going.)

What is it? Can I stop it?

  • Still a problem in 2018 with High Sierra. I wonder if corporate nannyware is to blame? This happens on my work computer. (I see it taking 99–100% CPU.)
    – Alan H.
    Sep 13, 2018 at 20:20

4 Answers 4


The manpage says:

 pkd -- management and supervision daemon for plug-in services

 pkd [-v]

 pkd manages plug-ins for the PlugInKit subsystem. It is a classic launch
 agent managed by launchd.

Sounds pretty safe to kill it off, by opening a terminal and running:

launchctl stop com.apple.pluginkit.pkd

It should restart itself whenever it's required (possibly immediately).

  • 5
    I tried what seemed like a safer approach: launchctl stop com.apple.pluginkit.pkd && launchctl start com.apple.pluginkit.pkd. My CPU usage went down a lot, and everything seems fine still.
    – Ken
    Dec 25, 2015 at 20:09
  • I've found that running App Tamer and setting it to a 1% processor limitation is a safer and more easily monitorable solution vs altering things permanently.
    – ylluminate
    May 14, 2016 at 19:28
  • It just restarts directly after killing it off, and returns with CPU usage of >100% with me. There has to be a better fix for this than just killing it off? Edit: I just figured out I'm running Cold Turkey, which might be the culprit. Can't kill that program until 15:30, so will try it out at that time.
    – Rvervuurt
    Apr 26, 2017 at 10:35
  • I have the same issue, and App Tamer does not help. As soon as pkd is running, the whole system becomes unusable. How can identify the root application that is responsible for starting pkd?
    – beta
    Apr 8, 2020 at 20:58

I uninstalled all plug-ins to my Safari and that cured the problem.......very annoying process

  • 2
    Please could you edit your answer to mention which Safari plug-ins you had. This may help others better isolate the cause of the problem. Jun 29, 2016 at 8:04

If you use the Roboform plug-in with Safari, you might be having a known issue with CPU usage that can be fixed only by removing it.

More info: https://discussions.apple.com/message/30212342#message30212342


I killed Tunnelblick and Karabiner-Elements, then force-quit pkd in Activity Monitor, then restarted Tunnelblick and Karabiner-Elements. Fixed the problem.

Just killing pkd alone did not.

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