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Is there anything in the current Firefox similar to the Task Manager in Google Chrome? (Shift + Esc)
There is something that occasionally takes up enough CPU to make Firefox unresponsive - but with multiple windows, each with a dozen or so tabs open, trial & error is going to take a while.
chris
Posted 2011-01-18T21:55:15.867
Reputation: 8 607
307
Resource usage can be monitored via the about:performance page which goes as Task Manager since Firefox 64. It had a major overhaul and now gives much more detailed insight into the performance of tabs and add-ons.
UnclickableCharacter
Posted 2011-01-18T21:55:15.867
Reputation: 3 243
13That's nice. However, I have a 100% CPU "Web Content" process which doesn't show up here. – Matthias Urlichs – 2019-07-06T10:43:47.620
45
about:memory shows Firefox's memory usage details. There's also a button on that page that allows you to minimize memory usage.
tomorrow__
Posted 2011-01-18T21:55:15.867
Reputation: 927
3Well mate, it seems to me this question is about CPU usage, not memory... – Luís de Sousa – 2014-07-05T18:33:15.627
It has nothing to do with CPU consumption. – UnclickableCharacter – 2016-06-13T13:20:44.700
13Obviously it's not the same as CPU usage, but in my experience they're very often correlated. After killing the biggest memory-hogging tab, CPU usage & lagginess often drop noticeably. – peterflynn – 2013-08-22T04:16:11.883
13Obviously it’s not the same as CPU usage, but in my experience they're very often correlated. @ytpete, then you frequent a narrow subset of webpages because there is absolutely no reason that they would necessarily be linked. It’s simple enough to have a 1KB webpage that has JavaScript with an infinite loop and thus 100% CPU load and another with 100MB of images that uses no CPU. – Synetech – 2013-11-15T03:24:18.653
9about:memory shows Firefox's memory usage details. There's also a button on that page that allows you to minimize memory usage. Does that page have CPU load information? If not, then what does this have to do with the question asked? This “answer” should be a comment, not an answer. – Synetech – 2013-11-15T03:25:06.237
3@Synetech It's been many years since a simple JS infinite loop would do much: Firefox and most other browsers put up an "unresponsive script" message after a few seconds of that, and then the loop gets cut off. – peterflynn – 2013-11-15T07:46:35.203
6This worked great for me. While it's true that a small Javascript loop can hit the CPU without using memory, that's not what what most webpage scripts are doing -- they are making remote calls, updating and manipulating the DOM, getting invoked by plugins (like Flash), etc. All these things can result in increased memory usage (especially if the page is slowly leaking objects). I found the culprit tab, closed it, used the Minimize Memory button, and Firefox was running smooth. Thanks again! – Nick – 2014-05-09T17:02:53.650
11
The first likely culprit is Flash. Kill Flash - now.
Then it may be rogue Javascript code. Firefox's Javascript Deobfuscator extention lets you watch the count of Javascript function calls :
It is not a measure of CPU usage, but a close enough proxy : find the function with a runwaway number of calls and you will likely have caught the culprit.
Jean-Marc Liotier
Posted 2011-01-18T21:55:15.867
Reputation: 459
1I don't have Flash installed and I have NoScript installed. This still happens on OSX even though I have two CPUs with 8 cores and 32 GB of RAM – chaostheory – 2015-08-17T06:46:14.910
6
Firefox 16 should introduce proper built-in profiler at last.
mk-fg
Posted 2011-01-18T21:55:15.867
Reputation: 69
1Apparently, this profiler was never introduced. The link provided is dead at this moment. – Luís de Sousa – 2015-09-25T07:27:08.637
Link is there but slow – Journeyman Geek – 2015-09-25T08:29:27.923
1Unfortunately the asker is using Firefox 3.x. :( – dangowans – 2012-09-16T22:28:28.630
2I'll settle for any version of firefox :) – chris – 2013-03-03T16:19:52.630
4
Except for already mentioned about:performance, there is a Task Manager addon that meant to be a clone of Chrome's Task manger.
czerny
Posted 2011-01-18T21:55:15.867
Reputation: 352
5Unfortunately not yet compatible with Firefox 57.0+ – Ed Randall – 2017-11-17T07:55:49.190
4
By using Flashblock and Nevercrash, now replaced with FlashStopper and UnloadTab you go a long way into blocking Flash or tabs, preventing CPU waste instead of tracking it. This holds, but less, for memory too. Flash, e.g. Youtube is prevented to start until you click on them, so you may launch them in several tabs and they wait for you to open the tabs. Tabs are uloaded from memory and idle until you reopen them and they are refreshed from the cache (if still available).
Shutting down the Internet for a while also works during the time you don't need it ;-)
Firefox fragments virtual memory so much that it's using an excessive amount of real memory (there is too much unused virtual memory in real memory). One needs to periodically stop and restart Firefox with the same pages. That will defragment its memory and the whole system will run faster by reducing the swapping.
On my Ubuntu system, real memory usage slowly climbs up to 98%. Then it's time to stop Firefox and restart it: it will then use less than 1MB of real memory instead of 3MB.
The same holds for Thunderbird..
Papou
Posted 2011-01-18T21:55:15.867
Reputation: 128
You might also have some success using the memory cleanup buttons in about:memory. I don't know if they will work as well as restarting Firefox. I would love to see some research on that. – joeytwiddle – 2015-06-30T13:24:41.897
Thanks. Did before, did it again, and real memory usage stays at 92% when clicking any. <br/> Regarding Flashblock and Nevercrash than I mentioned, they became incompatible with Firefox 34. A "did you upgrade to the latest version?" eternal problem. The wave is now Flashstopper and UnloadTab. Rather compatible but UnloadTab now unsurprisingly unloads tabs, needs no explicit "unloading of tabs" (fine) and "reloading tabs" acts as a page refresh (less fine, but using cache). One can set "Keep Address Loaded" when that reloading is breaking a page state you want to keep. – Papou – 2015-07-01T15:34:46.123
Thanks for testing. :) <plug> I use my own Hibernate Idle Tabs userscript with Greasemonkey. It navigates to a light holding page after the tab has been unused for some hours. Hibernation can be forced with its bookmarklet.
– joeytwiddle – 2015-07-02T09:31:23.3133
The following answer to another question may help you. The answer is written by the user "accolade".
XUL Profiler is an awesome extension that can point out extensions and client side JS gone bananas CPU-wise. It does not work on a per-tab basis, but per-script (or so). You can normally relate those .js scripts to your tabs or extensions by hand.
It is also worth mentioning that Google Chrome has built-in a really good task manager that gives memory and CPU usage per tab, extension and plugin.
Let me add some more info to accolade's answer. As of January 2012, the latest version of XUL Profiler is 1.0.4, released December 2008. It's only certified compatible with Firefox 2.0 - 3.6.*. So it clearly needs a new maintainer.
I wonder if there's any way to force the extension to work on newer Firefox versions.
Also, I wonder if it works well to downgrade Firefox temporarily in order to use XUL Profiler with your existing tabs on a certified-compatible Firefox version.
jasonspiro
Posted 2011-01-18T21:55:15.867
Reputation: 309
1
Here around 20% cpu was not accounted for by about:performance .
Turning off "Enable add-on debugging" checkbox in about:debugging got rid of this extra cpu usage.
You could also turn off this add-on debugging in about:config. Set either devtools.chrome.enabled or devtools.debugger.remote-enabled - or both - to off.
For more see about:debugging - Firefox Developer Tools | MDN
Alban Browaeys
Posted 2011-01-18T21:55:15.867
Reputation: 29
0
CPU Usage monitor addon served me well
Philippe Gachoud
Posted 2011-01-18T21:55:15.867
Reputation: 545
1How does it address the question, i.e. finding the particular tab? – UnclickableCharacter – 2018-08-13T16:49:13.737
0
Do you have Flashblock or NoScript installed? Especially if not, I'd try to look into the flash-heavy tabs first. I've also seen lots of eBay tabs grind Firefox to a halt, albeit that was a while back (when I was actually using eBay).
farfromhome
Posted 2011-01-18T21:55:15.867
Reputation: 537
2This really should have been a comment as it obviously requires clarification from the OP. – Burgi – 2016-07-01T07:39:12.967
Yes to both, as well as ad-block plus. But there's still something that's periodically using CPU. – chris – 2011-01-31T19:16:59.530
Then my next thought would be JavaScript-heavy sites that you allow through NoScript. – farfromhome – 2011-01-31T19:38:43.560
@Synetech, there may be no need for a process viewer, but for exactly the reason in the question there is very much a need for whatever you'd call a task manager that deals with memory and CPU usage at the tab level. As of mid 2015, there is still no tab resource viewer, but there is a project called Electrolysis which is splitting Firefox into (initially) two processes (for content and UI respectively) followed by further sub-divisions presumably to follow the Chrome model, at least loosely.
– Bob Sammers – 2015-08-04T10:40:10.290as of August 2015, these two extensions show Memory usage of the tab:
– tuk0z – 2015-08-27T20:37:39.050tabSizeTooltipandTab Memory Usage(while Memory's not CPU it's a strong indication as quoted by Kal and Peterflyn). Also Multi-process is coming soon to stable Firefox it's called "Electrolysis" alias "E10s" reddit thread.Possible duplicate of How to findout which firefox tab is using most CPU or memory?
– akostadinov – 2016-01-07T17:24:39.6831
Five years on and nothing of the like has ever been provided by Firefox. Those users interested in having such a feature are encouraged to back this feature request.
– Luís de Sousa – 2016-05-12T12:22:55.453Add statically-updated, per-tab CPU and RAM monitor – UnclickableCharacter – 2016-06-13T13:24:40.253
1No, there is no way to natively do this. I won't post an answer though because there might be some third-party solution. – Sasha Chedygov – 2011-01-31T00:34:55.047
I found this via google, it's a plugin. https://addons.mozilla.org/en-US/firefox/addon/bartab/ ...Makes it so (supposedly) the tab doesn't use resources until you click on it and are actively viewing it. From the user comments it may not work exactly as advertised, and apparently in firefox4 this is native behavior without the plugin. Personally I'd try ff4 if you aren't already.
– CreeDorofl – 2011-03-27T21:27:17.5101Firefox doesn’t use separate processes for each tab and plugin like Chrome does, so it has no reason to have a task-manager like Chrome’s. – Synetech – 2011-08-27T03:48:03.153
@chris: Ah right, they switched to a faster release model somewhere this year... – Tamara Wijsman – 2011-11-26T19:55:34.197