topic Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory. in Discussions

"FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Ikram_Hasan — Wed, 16 Mar 2022 03:15:46 GMT

Hello:

I use the M1 MacBook air which has 8 GB of RAM. I use it with a 4k 144Hz monitor.

I was searching for a browser that can take advantage of my 144Hz monitor and run smoothly. Safari works only 72 Hz and chrome initially runs at 144Hz but gradually it becomes choppy after using it for 10 minutes.

Firefox is the only browser that can sustain the 144Hz and everything runs very smoothly.

But here is the problem I am facing with Firefox. After 30 to 40 minutes of use, my whole laptop froze. When I checked the Activity Monitor it shows that "FirefoxCP Isolated Web Content" is taking 10+ Gbs of memory.

Then I closed Firefox, everything goes back to normal. Then I opened Firefox again and closed all the tabs and put my MacBook to sleep. When I opened my MacBook, the laptop is already struggling to do anything. There was no tap opened and even in the laptop sleep mode"FirefoxCP Isolated Web Content" is gradually taking 12+ Gbs of memory.

I really want to use Firefox. I have tried all the browsers and Firefox is the only one that can run smoothly on my 4k 144Hz monitor.

So I am requesting you to help me solve this issue.

Thank you.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

rl398363 — Tue, 05 Apr 2022 11:34:37 GMT

I have the same issue: If i only want to kog in to https://wertpapiere.ing.de the Web Cont or the Isolated Web Contant goes up to 10, 18 or 28 GiB and nothing works. After a min it go bach to 10 or 2,4 GiB, but this is also to much. Using Linux Mint, Aktual hardware, so this should be ok. With chromium this same window needs 800 MiB, also much but better. Any sugestion to stop the virtual memory?

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

brconflict — Sun, 10 Apr 2022 18:11:23 GMT

Same issue here. If you compare FireFox's M1 Mac's memory utilization in the FF console vs. the Mac's Activity Monitor, they're very different. Isolated Web Content is a rampant memory consumer.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Qlonyanko — Thu, 14 Apr 2022 06:39:48 GMT

I'm using iMac 27' (2017) with Intel i7, Radeon Pro 580 and 32GB memory. macOS is version 12.3.1.

And I have the same issue.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

jpdemers — Wed, 25 May 2022 09:27:12 GMT

Same issue here, M1 mini with 8GB RAM, and between Firefox itself (1.35 GB) and FirefoxCP (1 GB) I'm using up about a third of my RAM just for the browser. I have other apps open (MS Word, Preview, Thunderbird) and can barely get anything done without quitting FF. Latest version (100.1) of FF, which really should have addressed this by now.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Kailinu — Wed, 01 Jun 2022 08:59:18 GMT

Same here on a Macbook Pro 2015 with Iris Graphics 6100 and 16 GB of RAM. The moment I launch Firefox it uses 35 GB of virtual memory, then jumps back and forth to 43 GB and then eventually stabilize at 35 GB. I've disabled all the add-ons but did NOT uninstalled them. I have five tabs open and also unpinned all the pinned tabs that I usually have for emails or messages. However swap memory is 0 but it's easy when you only just rebooted.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Ss — Sat, 11 Jun 2022 23:59:06 GMT

For me, it not only uses up memory, but also hogs the CPU usage. Any solutions from the Firefox guys yet?

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

jpdemers — Sun, 12 Jun 2022 19:58:07 GMT

Activity Monitor shows one instance of 'FirefoxCP Isolated Web Content' for each tab that's open. Right now, I have six tabs open, and six instances running, and each is using 300-600 MB of memory. I believe that this is, essentially, the page content, making it instantly available for scrolling - is it possible that those clickbait-type pages with infinite scroll-down might consume more and more memory as you scroll?

If you have an instance of 'FirefoxCP Isolated Web Content' gobbling memory, refreshing the responsible tab should solve the problem, but there's no obvious way to know which instance corresponds to which tab. (You can use Activity Monitor to quit an instance, and see which tab crashes, but you'll have to refresh the tab to re-load the content.)

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

teledyn — Tue, 14 Jun 2022 23:09:02 GMT

Using Ubuntu 22.04 with 12GB ram I get the same problem, and while ctrl-q will exit Firefox when the CPU gets around to it, one process remains and that retains ALL of these greedy processes.

As someone else said, I really want to use Firefox, but if it is only able to handle half a dozen tabs, it's not for me 😔

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

m21e-de — Thu, 16 Jun 2022 19:16:00 GMT

I too have the same Problem on a M1 Macbook Air base model with the Version 101.0.1 (64Bit) and Monterey 12.4

Firefox Isolated web content

brdrcrzy — Thu, 23 Jun 2022 15:39:38 GMT

On my Mac, my firefox windows slow down and my whole computer becomes a slug. My way to fix is to go into system monitor and kill all the "Firefox Isolated web content" processes. Some kill tabs, but most are just hanging out there with no processes but taking up bandwidth. This started a couple months ago. Whats up? If this continues I may be looking at a different browser as I can't continue like this.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

svdasein — Fri, 24 Jun 2022 03:48:28 GMT

I'm running Linux Mint and I'm seeing the very same sort of behavior. It looks like this:

I've ensured that I'm up to date w/ the linux distro and with firefox. And I think it started happening a handful of weeks ago.

Has anyone found a workaround for this?

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

AllUpINet — Sat, 16 Jul 2022 02:23:42 GMT

Hi All,

Same issue here. Firefox will also keep my computer awake after closing the top it can get very hot.

Hope someone figures it out soon. Thanks

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

pauljoy06 — Mon, 01 Aug 2022 11:08:03 GMT

I am facing the same issue and I am using Intel Macbook

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

pauljoy06 — Mon, 01 Aug 2022 11:13:00 GMT

My issue was happening due to some development work that I was doing. It's resolved now.

Re: Firefox Isolated web content

zumablu — Fri, 12 Aug 2022 15:32:52 GMT

How did you "kill" them? I can;t find a way to delete them.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Troncocionco — Sun, 21 Aug 2022 12:34:21 GMT

I had the same issue and although I'm sure which one was requesting all that %CPU, I solved it closing few tabs. Specifically there seems to be one which was stucked in a captcha checking task.

Re: Firefox Isolated web content

brdrcrzy — Wed, 24 Aug 2022 00:51:51 GMT

I'm running MacOS. In launchpad, in "Other" click on Activity Monitor. Look for the process and Force Quit.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

sactown — Thu, 25 Aug 2022 00:04:15 GMT

macbook pro running intel chips, same issue. Wish I could figure out which specific webpage causes this, I keep a lot of windows open.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

sherrio — Sun, 04 Sep 2022 11:56:25 GMT

Same problem on Macbook Pro, this started after the most recent update this week. FireFoxCP Web Content runs until the laptop is out of memory.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Abikitty — Tue, 13 Sep 2022 04:59:09 GMT

I have used FireFox for many years and would hate to give it up, but Firefox CP Isolated Web Content is at the tipping point of becoming what advice columnists call "a deal breaker." Just realized today that all the slowing I have been suffering from is not the fault of something I have done or a sign that my PC needs to be reset or recovered, but is actually built into FireFox. This is crazy!

I was about to start my computer on the path to doing a "recovery" and reinstalling the operating system for the third time tonight. Good thing I happened upon the true explanation here. I hate Edge, but I feel any other browser would be preferable to FireFox at this point. Hopefully someone in charge will wise up and get rid of this RAM gobbling monster.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Gnat — Wed, 14 Sep 2022 22:14:01 GMT

Why is there no response here yet from Mozilla?

I'm having to quit Firefox, then reload all my tabs, every other day. The problem is always "FirefoxCP Isolated Web Content" processes.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

m21e-de — Thu, 15 Sep 2022 07:27:41 GMT

My current solution is to use another Browser until this is fixed or until I stop caring to use FF

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

jpdemers — Thu, 15 Sep 2022 20:20:50 GMT

I don't think anybody has figured out yet why it happens, and under what conditions. I had the problem for a couple of months back in early spring, and then it went away as mysteriously as it came.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Gnat — Thu, 15 Sep 2022 21:38:11 GMT

It would just be REALLY NICE if MOZILLA would post here to say, "Here's the latest we've figured out. Here's what we're doing about it. Here are a few helpful suggestions/workarounds in the meantime." Their memory-issue page doesn't even mention Firefox CP, let alone FirefoxCP Isolated Web Content. How about a useful info update, MOZILLA?

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

SUMOsJR — Mon, 19 Sep 2022 14:57:15 GMT

Hello All. FirefoxCP isolated web content is just a web content process. The process name may make you think the issue is Firefox specifically, however, In most cases this can be due to a website that is leaking stuff(<-- JS heavy websites sometimes keep references to objects they aren't actively using and you end up with bloat in that process). To narrow down what site may be causing this head to about:processes. There you will see which website uses how much memory and CPU. This will let you close/kill processes, lists PIDs. Though please note that closing processes can lose your state on those webpages.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

teledyn — Mon, 19 Sep 2022 16:39:32 GMT

Thanks for this. Your explanation is consistent with one particular page that I found had crashed when I used kill on the errant process. It was an animated map of a large graph that could very well have a memory leak, and now with about:processes, which I didn't know, I can maybe confirm this.

Is there an about:about page?

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

SUMOsJR — Mon, 19 Sep 2022 17:07:22 GMT

Well, I just did a quick look through the Support Knowledge base and I didn't find a specific article that speaks to all of those about: pages. I also checked with our support content team and we don't have a unified article about all of these because regular users don't know or use them normally. Additionally, You could really mess things up changing stuff like in about:config(<-- be CAREFUL). In any case though, here are the ones I can think of of the top of my head.

* about:processes - page to check on process performance (high CPU usage issues do to websites are easily seen here)
* about:performance - page to check performance of sites and site related content (same as above)
* about:memory - 🤔 I forget, but likely to check memory issues and get logs
* about:profiles - goes to page to manage your profiles
* about:config - goes to the advanced config page (CAUTION <-- you could mess things up here so be careful!)
* about:preferences - goes to your settings page
* about:addons - goes to your personalize settings page in settings

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

SUMOsJR — Mon, 19 Sep 2022 17:42:41 GMT

almost forgot about:support Doh

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

teledyn — Mon, 19 Sep 2022 18:43:04 GMT

Thanks!

You do realize of course that I went straight to about:config - you should have said, "a bunch of boring things, no one goes there anymore" 😂

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Gnat — Tue, 20 Sep 2022 02:43:00 GMT

On the bold & hopeful assumption that SUMOsJR's tag 'Employee' means employee of Mozilla, HUZZAH! Thanks for getting back to us on this! I'm not a programmer or techie, so my eyes immediately swim when I see pp. like about:memory (or freak re about:config). But about:processes & about:performance look more my speed.

Re: Firefox Isolated web content

MikaC — Wed, 12 Oct 2022 22:26:03 GMT

You Force Quit the process in the Activity Monitor. Select the process that's hogging memory, then click the stopsign with the x in it a the upper left of the Activity Monitor screen. Choose "Force Quit." Voila! Instant reduction of memory & CPU usage. If that process corresponds to an open tab (which it often does), you can just restore the tab if you need it. When it comes back, it's much less processor-demanding.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

DClougher — Tue, 22 Nov 2022 14:58:04 GMT

Geez guys, you almost saved my life and sanity with these posts. My issue on my mac was more about energy and the battery NOT charging because of some pages/sites. However, you lost me when it came to "about:processes" where do you find those? considering I'm using a French version of FF? 'cause would love to identify which page caused the problem, and not just blindly kill it (the FirefoxCP Isolated Web Content) in the Monitor

OK. Got it. So for newbies like me the answer is:
Just Type "about:processes" in the address bar of a new tab/page and… Tadaaa!

A whole new world of possibilities just opened in front of your eyes (and your mac will come back to life)

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Abikitty — Wed, 30 Nov 2022 06:55:50 GMT

It recently went away for me, too, maybe a couple of weeks ago, as mysteriously as it came. Could it be that an update addressed the problem? Anyway, it got fixed just in time, as I had begun practicing using Edge, and I still hate it as much ever. Hard to use, and although I imported my FireFox bookmarks, they and other favorites are far far away from being handled intuitively. Now I can stick to FireFox, except on the rare occasions when Microsoft has Windows 10 set up so that clicking on certain things that call for Internet use brings up Edge (even though FireFox is set as the default.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

jpdemers — Wed, 30 Nov 2022 13:19:20 GMT

The problem isn't with FireFox, but with certain web sites. Either (1) the site owner has fixed their code, or (2) you aren't visiting the offending page anymore.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Sciroccogti — Wed, 30 Nov 2022 13:48:42 GMT

It's definitely FireFox's problem.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

shadowplumber — Sun, 04 Dec 2022 03:59:27 GMT

Intel chipped MacBook Air: same exact issue. I have single tabs eating up over 2GB of ram, which for my puny 4GB is not good for the ye ole compooter. I’ve switched back to Chrome because of the issue. It’s a crying shame.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

seriochka — Wed, 07 Dec 2022 22:01:30 GMT

Read through this... experiencing the same thing on my 2012 Macbook Pro with 16GB of RAM. When I killed the offending CP process, it crashed my LinkedIn Tab only (https://www.linkedin.com/feed/). Lots in this typically and different types of content, but yeah...

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

baldfury1 — Mon, 12 Dec 2022 21:23:13 GMT

using activity monitor, click on the firefoxCP isolated web content hogging memory and then the x. the offending tab in my case was hootsuite. told me "Gah. Your tab just crashed." It's not firefox but what is in the open tabs......

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

RedRockRick — Wed, 14 Dec 2022 15:11:35 GMT

I came to this thread because I was looking at my activity monitor and saw that there were 13 instances of "FirefoxCP Isolated Web Content" open. I have a Mac Studio with 128 GB of Memory and the Apple M1 Ultra Chip. I also have the Apple Studio Display and 2 additional 27 in Samsung monitors.

Currently I have 10 tabs open and Firefox is using about 7.5 GB of memory. I was shocked. I also have Safari open with 13 tabs and it is only consuming less than 1 GB of memory. I am not having any issues like you describe but it seems to me that you should not have the issues with Safari that you are having. Could this be a graphics card issue?

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

RobotSausage — Sat, 17 Dec 2022 17:09:01 GMT

I just had this same issue. After reading some of the replies here, I realized I had TWO Firefox tabs open with two different Amazon products I was keeping an eye on. I closed those two tabs and the CPU fan of the 2017 MBP almost instantly started to calm down and the machine resumed its usually snappy response times.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Alexander-Wilms — Fri, 24 Feb 2023 17:44:07 GMT

Same issue here. Firefox Isolated Webcontent process took up 8 GB of RAM:

https://www.welt.de/vermischtes/article243942169/Patricia-Schlesinger-klagt-auf-Ruhegeld-Ex-Intendantin-will-ueber-18-000-Euro-pro-Monat-vom-RBB.html

Firefox 109.0.1 (64-Bit)

Operating System: openSUSE Tumbleweed 20230222
KDE Plasma Version: 5.27.0
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8
Kernel Version: 6.1.12-1-default (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-7700K CPU @ 4.20GHz
Memory: 15.6 GiB of RAM
Monitor: Dell Inc. S2721DGF running at 144 Hz

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

BaBa2023 — Sat, 25 Mar 2023 02:52:38 GMT

Same here. It immobizlsed my new mac and my new macbook pro, both with Ventura 13.2.1.

I used to love mozilla. But I'm switching to chrome. Trouble not worth it. Thanks for the tips

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

FirefoxCPUwtf — Sun, 07 May 2023 15:18:26 GMT

same issue regardless of operating system. FirefoxCP Isolated Web Content is using 100% CPU. It must have something to do with cross-site cookies being blocked. Either a mozilla oversight or websites trying REALLY hard to see cookies in your other sites

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

phr — Tue, 09 May 2023 22:40:16 GMT

Well, a single tab could easily consume 1 GB of RAM.

Trying using Google Maps for some time - zoom in/out, switch to Map/Sattelite/StreetView etc.

But it's the same in e.g. Chrome

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

ClaudiLopez — Wed, 24 May 2023 21:35:24 GMT

Ha ha! So true....

(Kids, now DON'T look to see what's behind this door...) :'D

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

ClaudiLopez — Wed, 24 May 2023 21:35:45 GMT

Thank you soooooo much!

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

bulgroz06 — Wed, 31 May 2023 18:02:53 GMT

I have the same issue on Ubuntu and Firefox. The Isolated Web Content process appears each time I log into my bank account and disappears when I log out or delete the tab. The %CPU starts with 400% then stabilizes at 100% causing my fan to accelerate very strongly. Surprisingly this does not happen with the Brave navigator.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

akonit — Tue, 18 Jul 2023 16:49:05 GMT

I opened `about:processes` in Firefox and fond out that opened windows (tab) consumes an lot of energy, and this was simple (VisualStudio site)[https://code.visualstudio.com/updates/v1_80] so I just closed this tab and FirefoxCP Isolated Web Content resumed to consume normal amount of energy.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

akonit — Tue, 18 Jul 2023 16:52:00 GMT

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Abikitty — Sun, 17 Sep 2023 06:51:39 GMT

Nothing has worked for me, including getting rid of most extensions, including Ad Block. I'm angry and also feeling very sad because I have been using FireFox almost from its beginning and loved it. I love the many beautiful themes people have made for it and many of its extensions, but it has reached the point where I have to waste a great deal of time even just trying to close it. Hitting the "X" over and over, and using ESC can still freeze things for an indefinite time, and Microsoft Word has become abysmally slow. Typing an email gets terribly slowed down after a while, every time, unless it's quite short. The problems went away after I decided to give up on FF and (in the last few days) switched to Chrome. I don't like it as much as FF, but at this point, I can't do my job using FF, and it is just too much to handle. Once in a while, I open FF for some brief task. Recently, I found a long list of suggestions from Mozilla as to how users can try to fix the problems. It should not be up to the users to spend hours trying this and that, while waiting 1, 5, 10 minutes --or who knows how long it will be-- at each juncture because FF keeps freezing. Years ago, with one of the early less stable versions of Windows, I once got rid of a whole PC for behavior like that, though it meant buying a new one, so why keep putting up with it in a browser? If Mozilla gives up on what seems to be a mad experiment and lack of respect for its users, there is a chance I will come back. But for now, I am learning how to use Chrome and have made it the default.

By the way, long ago, I once tried refreshing/resetting FireFox to solve another problem, and only succeeded in losing all my bookmarks, so once bit, twice shy, so far as trying that solution goes!

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Abikitty — Sun, 17 Sep 2023 06:49:21 GMT

" It's not firefox but what is in the open tabs"--Not in my case! Even when I close all tabs but two belonging to blogs I like, which never used to cause any problems, it is still sucking up incredible amounts of memory.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Gnat — Sun, 17 Sep 2023 07:30:38 GMT

We [OK, I] really need someone with authority at Mozilla to chime in here and say, "We are working on it and will have this handled for you, in a new update, before the month it out."

"Connect Community" is swell, but it should not take the place of concerted action on the part of Mozilla to take care of a longtime user concern.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

privateusername — Sun, 10 Dec 2023 21:41:10 GMT

Wow. You're so right. 😮

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Infinity-AX — Sat, 17 Feb 2024 01:46:52 GMT

I also have the same issue on my MSI Katana laptop running Linux Mint. This could be a memory management bug, as I experience similar symptoms when I accidentally forget to release the memory in my C programs. My remedy for this issue is to check and see which tabs are responding or working correctly and close the ones that are not. Tabs that are not responding or working are usually the ones hogging the resources. Your solution to close the browser, wait a few moments, and reopen it is also valid. I would also suggest closing any tabs you are not using and closing the browser completely when not using it. You can also try removing any extensions you don't need and update the browser and extensions.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Mizar — Sat, 17 Feb 2024 19:46:54 GMT

You could try setting at about:config

dom.ipc.processCount.webIsolated to 0

dom.ipc.processPrelaunch.fission.number 0

fission.webContentIsolationStrategy to 0

and

browser.tabs.remote.separatePrivilegedMozillaWebContentProcess to false

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

ejm554 — Mon, 18 Mar 2024 17:26:38 GMT

Thanks, SUMOsJR! The fan on my Mac had been running non-stop even though Firefox was the only app in use. The macOS Activity Monitor showed several Firefox processes were using more than 100% of the CPU. I used your advice regarding about:processes, and I was able to identify the offending domains/pages. After closing the pages, the fan promptly stopped and the Activity Monitor showed CPU use had returned to a normal level.

Does anyone else think it could be useful if Firefox would notify me if/when there are pages that are leaking/bloating?

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Mizar — Mon, 18 Mar 2024 22:08:44 GMT

@Abikitty wrote:
I have been using FireFox almost from its beginning
You've been here since Netscape? 🤔

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

philm — Thu, 30 May 2024 00:27:35 GMT

about:about is very handy, too 🙂

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

Sandstrom — Thu, 08 Aug 2024 07:49:04 GMT

Would be great if the domain name would be shown in the activity monitor (macOS) for these (Safari does that!).

That way, it would be less confusing, and also easier to ask lazy web developers to optimize their site better.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

3phase600V — Sun, 20 Oct 2024 19:03:47 GMT

I see this is an old post, but for anyone coming here from a search (as I did)...

I often have 50+ tabs open in several windows on my Mac (needed for work). In Activity Monitor I just clicked the high usage FirefoxCP isolated web content and the clicked on close. I saw the offending tab stop responding. It was from a well known retailer, but some issue on their side. Mac running smoothly again.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

asthetik — Mon, 18 Nov 2024 11:40:36 GMT

Until now, this problem still exists on my M1 Max...

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

dharter — Fri, 03 Jan 2025 18:21:25 GMT

I wrote this perl script to kill all the isolated web processes. If you find that a tab has crashed, you can just reload it. You run it by typing the script name followed by the "kill" parameter. It applies that to all the processes which have the description of Isolated Web.

#!/bin/perl
# the first parameter is the command that you want for each process
# "kill"
#print "parameter 1 ", $ARGV[0], "\n";
$command=$ARGV[0];
system ("ps -e >proc_list;");
open (IF,"proc_list");
while (<IF>) {
$proc_line=$_;

if ($proc_line =~ /(Isolated Web Co)/) {

print " have a web process ", "\$1- ", $1, "\n";
print "proc_line- ", $proc_line;
$proc_line =~ /^\s*([0-9]+)/;
$proc=$1 ;
print "process number ","$proc", "\n\n\n";
#print $command $proc;
system("$command $proc");
}
}
close (IF);

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

s3c — Fri, 07 Feb 2025 11:04:02 GMT

Can't find it now for the life of me, so sorry for no credits given, but some guy posted a perl script for closing those processes. That script looked like this:
```

#!/bin/perl

# the first parameter is the command that you want for each process

# "kill"

#print "parameter 1 ", $ARGV[0], "\n";

$command=$ARGV[0];

system ("ps -e >proc_list;");

open (IF,"proc_list");

while (<IF>) {

$proc_line=$_;

if ($proc_line =~ /(Isolated Web Co)/) {

print " have a web process ", "\$1- ", $1, "\n";

print "proc_line- ", $proc_line;

$proc_line =~ /^\s*([0-9]+)/;

$proc=$1 ;

print "process number ","$proc", "\n\n\n";

#print $command $proc;

system("$command $proc");

}

close (IF);
```
it didn't work on my macbook pro m1 (8gb), so I fixed it for me.
Prerequisites:
```
brew install perl
echo 'export PATH="/opt/homebrew/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc
which perl # this install path should match the shebang (first line) of the script
mkdir -p ~/scripts
touch ~/scripts/firefox--kill-isolated-processes.pl
chmod +x ~/scripts/firefox--kill-isolated-processes.pl
nano ~/scripts/firefox--kill-isolated-processes.pl # and then paste in the script
```
Script
```

#!/opt/homebrew/bin/perl

use strict;

use warnings;

# Default to regular kill, allow override with -9 for force kill

my $command = $ARGV[0] || "kill";

# Validate command

die "Invalid command. Use 'kill' or 'kill -9'\n"

unless $command =~ /^kill(?:\s+-9)?$/;

print "Using command: $command\n";

# Open process list from `ps aux` directly

open(my $IF, "-|", "ps aux") or die "Could not execute ps: $!\n";

my $killed_count = 0;

my $total_memory = 0;

while (<$IF>) {

# Match Firefox plugin-container processes that are for browser tabs

if (/plugin-container.*-isForBrowser/) {

# Extract PID and memory usage (fields 1 and 3 in ps aux output)

my @Fields = split(/\s+/, $_, 11);

my $proc = $fields[1];

my $mem = $fields[3]; # Memory percentage

if ($proc =~ /^\d+$/) {

print "Found Firefox tab process $proc using $mem% memory\n";

$total_memory += $mem;

# Execute the kill command

my $result = system("sudo $command $proc");

if ($result == 0) {

print "Successfully killed process: $proc\n";

$killed_count++;

} else {

warn "Failed to kill process $proc (error: $?)\n";

}

} else {

warn "Could not extract PID from line: $_\n";

}

close($IF);

print "\nSummary:\n";

print "Processes killed: $killed_count\n";

printf "Total memory freed: %.1f%%\n", $total_memory;
```

Usage
```
#either
~/scripts/firefox--kill-isolated-processes.pl
#or
~/scripts/firefox--kill-isolated-processes.pl"kill -9"
```

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

DR_USA — Thu, 08 May 2025 18:05:51 GMT

The offensive web sites also seem to do a lot of auto updating (like FB and GMail). I found that by hitting the refresh button on those, then clicking the "X" before it fully refreshes stops this behavior. My FB tab went from using 490MB down to 75MB. When I want the page to update, I just refresh it.

But this is annoying. There should be a setting in Firefox to "Stop Pages from Automatically updating."

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

freshdsoe1 — Mon, 26 May 2025 23:36:35 GMT

This seems to still be happening. I have a macbook air m4 brand new from today with 24g of ram and firefox is eating way to much ram

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

SerZ — Wed, 08 Oct 2025 07:45:50 GMT

I’m experiencing the same issue on Ubuntu 22.04.5 LTS (64-bit) with Mozilla Firefox version 143.0.4 (64-bit). Sometimes the browser crashes completely, and other times it refuses to start again after being closed. When that happens, I have to manually kill the Firefox process using htop to get it working again.

Re: "FirefoxCP Isolated Web Content" is slowly consuming all of my Mac's memory.

smeetster — Tue, 04 Nov 2025 08:23:56 GMT

Here we are another year later. Same problem. Youtube in a tab seems to eat all memory and CPU. I sure hope somebody is working on fixing this.