Apple Intelligence now features Image Playground, Genmoji, Writing Tools enhancements, seamless support for ChatGPT, and visual intelligence.

Apple Intelligence has also begun language expansion with localized English support for Australia, Canada, Ireland, New Zealand, South Africa, and the U.K. Learn more >

You can make a difference in the Apple Support Community!

When you sign up with your Apple Account, you can provide valuable feedback to other community members by upvoting helpful replies and User Tips.

Looks like no oneā€™s replied in a while. To start the conversation again, simply ask a new question.

Safari Web Content high CPU usage

Hi everyone!


Safari become very lag when I open a new tab or pages, and when I checked Activity Monitor, the one that made my mac lag is Safari Web Content, it can eats 80-90% of CPU.However, it only happened if I open new tab/pages. I never experienced lag with other browser such as Firefox before.


Anyone ever experienced this? Any suggestion or solution will be appreciated.


Thanks.

Macbook 13 inch late 2008 model, Mac OS X (10.7)

Posted on Jul 20, 2011 1:10 PM

Reply
Question marked as Top-ranking reply

Posted on Nov 6, 2013 1:45 AM

I had exactly the same issue!! 100% CPU on Safari Web Content. the site causing it was an oxford university Mirror hosting site.. I reset safari.. nothing. I formatted my HDD and clean installed mavericks. opened safari with just my Apple ID registered... nothing changed! after a minute or 2 it was 100 % again.. spoke to many tech guys and nobody could figure out what it was!


I was sat at my mac this morning making another Install USB for mavericks and decided to clean up my bookmarks and reading list entries..


There it was!! An XBMC download link in my reading list!! Deleted it and PROBLEM IS SOLVED!!


This has done my head in for a few weeks! been using google chrome ever since! ive now deleted it and i hope this can help others figure out the issues with their own machines!!


Hope this helps you guys!!!


Stuart

264 replies
Question marked as Top-ranking reply

Nov 6, 2013 1:45 AM in response to solidrocketbooster

I had exactly the same issue!! 100% CPU on Safari Web Content. the site causing it was an oxford university Mirror hosting site.. I reset safari.. nothing. I formatted my HDD and clean installed mavericks. opened safari with just my Apple ID registered... nothing changed! after a minute or 2 it was 100 % again.. spoke to many tech guys and nobody could figure out what it was!


I was sat at my mac this morning making another Install USB for mavericks and decided to clean up my bookmarks and reading list entries..


There it was!! An XBMC download link in my reading list!! Deleted it and PROBLEM IS SOLVED!!


This has done my head in for a few weeks! been using google chrome ever since! ive now deleted it and i hope this can help others figure out the issues with their own machines!!


Hope this helps you guys!!!


Stuart

Aug 2, 2012 9:06 AM in response to elpelso

Given what andrewfrommoleseyposted above, one other thing comes to mind: corrupt or stuck local storage data.. that AFAIK is also handled by 'Web Content'. What banking sites call 'downloading web apps' (that run in your browser). They store stuff in browsers, and buggy ones can become 'stuck'.


So one thing you might (also) want to try that works for me is an app that blows all browsers' (as in plural) cache, or cache that might not be easily accessible from within the browser itself.


My personal favorite is Cookie: http://sweetpproductions.com (click on the 'download arrow' to get the non-MAS demo version).


User uploaded file

This is just the global menu. For geeks it also has a nice main window that shows all the details of the cookies & cache that you're zapping. If the issue is a stuck database or cache, this might help.


As to WC also 'force quitting' Safari, this makes sense. Sorry for the geek logic, but why have Safari in an older memory state when you restart web content?


Again, this is something to try. If it does work for you (as it does for me) consider dropping some coin to the Dev.


-Leo

Oct 9, 2013 10:00 AM in response to scryedz

Safari web content 100% just by opening facebook.com?

User uploaded file

And with Firefox no worries:

User uploaded file

Tried it with extensions turned off in Safari having the same result.


I can reproduce this incident. This started after the (3 oct) recent Mac OS X 10.8.5 update.


Hope you guys at Apple will have a solution for this with the 6.1 safari.


For now, bye bye Safari you suck a lot of battery.

Sep 18, 2013 6:58 AM in response to hanshefu

Hi Hanshefu,


Apple employees rarely if ever participate in these forums which instead are for end users.


To submit an enhancement request,


http://www.apple.com/feedback/macosx.html


I think (but could be mistaken) that a workaround is to install more RAM (for Macs that have user-upgradable RAM; your MBA probably is not user-upgradeable).


Another possibility is that Mavericks might address this scenario with its RAM compression feature.

Dec 26, 2014 5:57 AM in response to PiersJEC

.


I had this problem too. You can see the thread I started here:

https://discussions.apple.com/thread/6725713



Solved the problem, at last.


Mostly it was 3rd party extensions, which were hogging CPU space. The worst offenders were: Omnibar, Genio and DivX. But the odd thing, is these were not showing in Safari Extensions (in the preference window). I found them in:

>Applications

>Library >Safari >Extensions

>Library >Cache >Safari >Extensions


Having deleted these extensions, I seem to be running normally.


Ralph

Apr 26, 2013 2:58 PM in response to Chrisndeca

I'm not sure the idle tabs idea would work, or isn't already partly implemented. I suspect certain sites that perform periodic updates while active do them in a quirky way that doesn't disturb Chrome or FireFox. It's just unclear whether Safari is less forgiving of those quirks, or is buggy itself. But if one of the active tabs was updating while the others were idle, it might well bring the browser grinding to a halt anyway.


I've scanned for the basic troubleshooting steps in this discussion, but either they're not here, or I missed them. They include:


  • Disable all extensions; uninstall the ones you don't use
  • Saving existing tabs as bookmarks (NOT as a reading list) if you want to reproduce them (otherwise just quit the browser).
  • Quit Safari (or Force Quit)
  • Open Safari again

    the default behavior is for Safari to open one tab with your preference of page; if all your tabs open again automatically, Quit Safari again, and reopen it with the shift key held down

  • Reset Safari for all settings except your passwords and Autofill
  • Of course sufficient RAM and hard drive space are assumed, so it's worth checking, if you haven't


One way of testing the waters is to open each page, one at a time, and leave it open for a certain period; and to add in one extension at a time. I presume that it's obvious, but it wouldn't be very productive to open all the tabs you had opened before to see what happened.


While having this problem intermittantly, I've observed a few things.

  • Having a Facebook page open makes it more likely that Safari overutilizes CPU

    I also have Chrome open in the background almost all the time

    • Facebook pages report problems several times each week in Chrome
    • While checking Safari CPU utilization in Activity Monitor, I have several times noticed Google Chrome Renderer at 100%, seemingly concurrent with Facebook problems
  • Another culprit appears to be one of several google.com pages
    • Google Drive is almost always open when Safari has problems
    • gmail some times reproduces the same problems


I also suggest checking whether DivX has been installed before, as some here report (and to uninstall it completely, which is documented elsewhere); and that earlier versions of the Spotify app cause problems either because of processes launched when the computer starts, or when the app is running. Check your Login items to make sure no unknown or abberrant process is launched on startup.

May 12, 2013 1:40 AM in response to JohnMM

I had the same issue with safari web content high cpu usage on a mid 2010 MBP (10.8.3). I installed ClickToPlugin, however, surfing the web with all plugins initially turned off isn't that much fun.


This morning I tried to uninstall all divx content and additionally uninstalled other third party codecs and everything is back to normal. Even with several flash videos playing simultaneously safari web content is at 60% cpu usage. This is only the first impression but hopefully it ll stay this way...


In detail I uninstalled Periana which contains all kind of codecs and I cleaned the remains of a forrmer DIVX installtion with the free version of cleanmymac and rebooted.


For playback of special codecs I still have VLC installed which doesn't seem to affect safari web content.


JohnMM wrote:


I'm not sure the idle tabs idea would work, or isn't already partly implemented. I suspect certain sites that perform periodic updates while active do them in a quirky way that doesn't disturb Chrome or FireFox. It's just unclear whether Safari is less forgiving of those quirks, or is buggy itself. But if one of the active tabs was updating while the others were idle, it might well bring the browser grinding to a halt anyway.


I've scanned for the basic troubleshooting steps in this discussion, but either they're not here, or I missed them. They include:


  • Disable all extensions; uninstall the ones you don't use
  • Saving existing tabs as bookmarks (NOT as a reading list) if you want to reproduce them (otherwise just quit the browser).
  • Quit Safari (or Force Quit)
  • Open Safari again

    the default behavior is for Safari to open one tab with your preference of page; if all your tabs open again automatically, Quit Safari again, and reopen it with the shift key held down

  • Reset Safari for all settings except your passwords and Autofill
  • Of course sufficient RAM and hard drive space are assumed, so it's worth checking, if you haven't


One way of testing the waters is to open each page, one at a time, and leave it open for a certain period; and to add in one extension at a time. I presume that it's obvious, but it wouldn't be very productive to open all the tabs you had opened before to see what happened.


While having this problem intermittantly, I've observed a few things.

  • Having a Facebook page open makes it more likely that Safari overutilizes CPU

    I also have Chrome open in the background almost all the time

    • Facebook pages report problems several times each week in Chrome
    • While checking Safari CPU utilization in Activity Monitor, I have several times noticed Google Chrome Renderer at 100%, seemingly concurrent with Facebook problems
  • Another culprit appears to be one of several google.com pages
    • Google Drive is almost always open when Safari has problems
    • gmail some times reproduces the same problems


I also suggest checking whether DivX has been installed before, as some here report (and to uninstall it completely, which is documented elsewhere); and that earlier versions of the Spotify app cause problems either because of processes launched when the computer starts, or when the app is running. Check your Login items to make sure no unknown or abberrant process is launched on startup.

Jul 23, 2013 1:56 PM in response to OmBass

A few of points:

  • it is possible to get Chrome to misbehave and to dominate CPU usage with a minimal number of open tabs; I don't know about FireFox because I don't use it often (it is deficient, for me, in a number of other ways).
  • I agree that, as a solution, reinstalling the OS is a poor choice, partly because people tend to migrate or reinstall things that might have caused the original problem; and because it is time-consuming and ignores diagnosis and troubleshooting.
  • Third-party add-ons, particularly those that launch with the System, are greatly suspect, but rarely discussed.


In recent years, these discussions have seemed to lean more toward, "why is Apple the problem?", than reflecting on systematic troubleshooting. Maybe there's a place for that; people have to find a place to vent their frustrations. But, for instance, if I had two cars that I fueled at the same gas station, and one always had problems with bad fuel, but the other ran reasonably well, would I blame the car or the fuel?


So is the symptom of using excessive RAM in Safari with multiple tabs open due to Safari alone? ...or to some persistent HTML in one of the tabs? ...or to a 3rd party process (initiated by, or independent of, a web page) conflicting with one of Safari's processes? And if the problem is with the HTML or another running process, is it a problem because Safari has a bug, or the because HTML or the process makes a questionable programming call?


I'm not trying to defend Apple here. I'm trying to point out that the issue is complex enough so that one can't easily assign blame. I'm also not dissing you - this is a frustrating problem that takes a lot of effort to solve, so I can understand you wanting to blame Apple.


Right now, I'm running 19 open tabs and Safari drifts between 2% and 6% CPU (while two Google Chrome Renderer processes consume more than 20%). I still have a few intermittant problems, but have eliminated most instances by using some of the suggestions in this discussion.

Jul 23, 2013 3:53 PM in response to OmBass

What helped me:


  • the biggest is to unistall DivX and all its traces; though it has an uninstaller, pieces of it persist in both the main and the user Library folder in multiple subfolders; and it has many versions.
  • when I say "3rd party processes" I don't just mean Safari plugins.
    • Are there items in your menu bar that may conflict (audio such as Airfoil, notification such as Growl, etc.)?
    • When you examine your login items in the Users & Groups System preferences, are there items that launch which you don't recognize or understand (or that you don't need)?
  • in Activity Monitor, when you scan the list of "all processes", are there items that you are surprised by, or don't fully understand? (many obscure things will be system processes, and typing their specific name into a search engine will quickly identify them; but some might be zombies launched from long dead programs)
  • Even if you have a new computer, did you use the utility when you started to migrate all your old apps and settings? That utility also brings over all the old cruft (preferences, application support, startup items, etc.) from every previous computer from which you migrated.
  • Eliminate all plugins from the Internet plugins folder that you don't explicitly use.


I haven't experienced Safari dominating CPU usage in weeks after checking the things I listed. But I haven't found one particular culprit, either. YMMV.

Jul 26, 2013 6:05 AM in response to scryedz

I've just logged out of Google, quit safari and restarted safari, and can confirm that this appears to have resolved my CPU usage issue! šŸ™‚


I also logged into a flash intensive site to see how safari performed compared to running the same site through chrome and found that safari performed better (from a CPU/Memory) perspective...


So to reiterate the steps i took to resolve the issue were...


  1. Open Safari
  2. Log Out of Google Accounts
  3. Quit Safari
  4. Restart Safari


šŸ˜ šŸ˜Ž šŸ˜€

Jul 20, 2011 6:26 PM in response to scryedz

Hi


How much RAM do you have installed on your computer? You ought to max your RAM if you are running Lion due to system and load requirements.


I'm seeing about 2 GB of RAM allocated to Safari Web Content (this is a new process introduced in Safari 5.1). However, I have 12 GB of RAM and an i5 processor on my iMac, so CPU draw is not signficant (about 6 percent).


Seems Apple has split in two the Safari process in 5.1 from the singular process used in earlier versions of Safari. Via Activity Monitor I now see "Safari" and "Safari Web Content".


Not sure exactly what drives the Safari Web Content process, however, large number of tabs open, and/or large number of extensions or plugins will require more RAM and CPU usage. In any event, the activity level and RAM requirements in this process seems excessively high. Perhaps others will add their experience here.

Jul 20, 2011 10:22 PM in response to Hawaiian_Starman

Hi! Thank you for the reply.


I already maxed out the RAM. My macbook can handle up tp 4 GB RAM. Also I noticed, my macbook become very lag if I open certain website, such as in this case Gizmodo.com, the fan ramp out suddenly, and Safari become slow and lag. When I open Gizmodo with Firefox nothing happen, the fan is quiet and everything smooth.

Is there something bad with my Safari, I just upgraded to Lion hoping to eliminate the problem I got when I had Leopard and Snow Leopard, but problem stil persist. šŸ˜•

Jul 21, 2011 4:38 AM in response to scryedz

May be a corrupt cache file.


Quit Safari if it is open. Then, go to your Finder and navigate to: Your User Library>Cache>com.Apple.Safari folder> there, move the Cache.db file to the trash. Then, Finder menu>select "secure empty trash". Restart Safari and try Gizmodo.com.


If the fans continue to ramp, try Safari from another User Account (same site). Let us know if you have excessive fan activity in the other account.

Jul 21, 2011 6:45 PM in response to Hawaiian_Starman

What I've noticed is that, over time, the Safari Web Content process eats up more and more RAM. When I first opened Safari just now, Safari Web Content was using ~160 MB of my 4 GB RAM. Now it is up to 327 MB, with 2 windows (each with 2 tabs) open. I restarted Safari because the Safari Web Content process was using over 1.5 GB of RAM, leaving me with only ~ 90 MB free RAM. That was with Safari, Groupwise (email program), Mail, Activity monitor, and Magic Prefs running.

Jul 21, 2011 11:38 PM in response to Hawaiian_Starman

Hi thank you for your suggestion, I've tried what you suggest by deleting Cache.db file, however the problem still persists. I tested Safari on another account by creating a test account, and suprised Safari do very well on test account, it didn't use high CPU process. I am not sure what happen, is it because I've used Safari for long time so it accumulated some junks, or maybe Safari extensions cause any conflict?

Safari Web Content high CPU usage

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple Account.