Sign up ×
Ask Different is a question and answer site for power users of Apple hardware and software. It's 100% free, no registration required.

I usually have several tabs open in Safari in the background, and sometimes I see it taking up an unusual amount of CPU (PluginProcess or WebProcess).

How can I figure out which tab (or tabs) is causing this? If there are no easy GUI solutions, I'm also open to Terminal-based techniques for finding the culprit. I hope not to have to do this very often.

(Note: I realize this is similar to an old question, but Safari has been updated since then and perhaps there are new techniques available.)

share|improve this question
did you find a solution for yourself in the meantime? I'm having the same problem, but mainly for excessive use of RAM which seems to be triggered by some few tabs: – MostlyHarmless Mar 23 '14 at 11:44

3 Answers 3

up vote 1 down vote accepted

For what it’s worth, I’ve checked both the Develop menu and the Debug menu in the latest (Version 5.1.4 / 7534.54.16), and couldn’t find any helpful features.

Develop menu:

Debug menu:

The debug menu can be enabled using the following command:

defaults write IncludeInternalDebugMenu -bool true
share|improve this answer
  1. You need Safari 6.1 or newer

  2. Enable Debug menu

    defaults write IncludeInternalDebugMenu -bool true
  3. Set "Use Per-tab web processes" and "Show Web process IDs in page titles" to on.


share|improve this answer
Good use of graphics – CousinCocaine Apr 10 '14 at 12:15

cmd ⌘+alt ⌥+AWindow > Activity may help you to identify which tab is the heaviest in activity if it is lasting long enough.

I must admit that all my tests where failure, but I'm mostly using web servers which are fast.

I also tested Debug > Show Frame Rate Meter (see Mathias Debug dropdown menu) which is a partial answer to the original question. You have to test it by reloading every tab and compare the output of the 3 meters to see who is the hog.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.