Firefox Community Forum

I have a HUGE problem with Firefox memory usage. Some open instances of firefox are taking anywhere from 600mb to 2.8gb of memory. Since firefox opens MANY instances even with only ONE active window, this very quickly uses all available memory (4gb) causing a full laptop crash.

More concerning is that CLOSING the worst instance of memory usage STILL leaves the single open page/tab open, so what exactly was the memory eating instance actually doing ???

I have included a screengrab of the many remaining instances of firefox in windows task manager AFTER closing the main culprit.

I have also included a screengrab of all the adblockers I use which I believed would limit unnecessary memory usage, but does not seem to be effective.

Many Thanks

i noticed that my laptop is getting too hot, when i opened task manger i found that Firefox is using a lot of ressources every time, i have a decent ram of 24GB and i7 7th gen plus an gtx1050, i don't think it's my work flow because i've been always using too much tabs without any problem, i suspect an update issue, what do you think ?

Power consumption of Firefox is so high that it nearly killed the display of my iMac. My screen started flickering with horizontal lines across the display. When i touched the screen, it was so hot that I could boil water using it. I did not realize that it was Firefox that was killing my PC until I looked at the power consumption (see the attached screenshot). I hope there is a solution to this since I really love Firefox and have been using it for well over a decade.

One page of Firefox 115.21 opened and Task manager memory usage for Firefox reports-:

1) 9,956 K 2) 46,288 K 3) 11,564 K 4) 55,268 K 5) 21,560 K 6) 9,996 K 7) 5,516 K 8) 302,924 K 9) 40,272 K

These are ALL marked Firefox and in order on my Task Manager, the Page 'opened' was Firefox help forum ,,,, some memory usage here, is this right????

Dave

I’ve noticed that Firefox consumes a lot of memory, especially when I have multiple tabs open. Sometimes, it slows down my entire system, and Task Manager shows Firefox using over 1GB of RAM even with just a few tabs. Other browsers like Chrome or Edge seem to handle memory better with the same number of tabs.

I’ve tried restarting Firefox, closing unused tabs, and disabling a few extensions, but the problem keeps coming back. I even checked techsquest.com for tips, but I’m still struggling. Are there specific settings, hidden features, or optimizations I can apply to reduce Firefox’s memory usage without sacrificing performance?

Here’s what I’ve already checked:

Firefox is updated to the latest version.

No unusual extensions running (just uBlock Origin and Dark Reader).

Hardware acceleration is enabled.

Any help would be appreciated—thanks in advance!

Firefox uses too much memory, with 1 tab 1GB+, and with 4 tabs all 3GB+, this is not normal, the forum topic did not help, reinstalled and did not help, there are no more than 6 extensions, and they consume only 160mb.

I have two Firefox tabs open on my browser. Task manager shows 35 tabs using 897 MB of memory. How do I make this stop? And why are so many tabs running? I have cleared cache, cookies, etc.

Is this a bug or config problem?

Occasionally, FF (Linux desktop) starts using a lot of memory. I kill tabs (sometimes it is OK to kill YouTube or X, sometimes not)

Eventually it starts impacting the system using so much memory. I terminate the FF instance. Often. More often than not. There is a separate task still running and I get the "Firefox is still running" when I try to restart. I then kill the remaining FF task via the OS or the process monitor. Then FF restarts.

Is this an issue with addons (I am running very few - uBlock Orign, and Privacy Badger and Cookie AutoDelete. Are the only ones active most of the time) Or is it an actual bug with garbage collection, and tasks getting away? Or is it an OS issue?

Firefox is running too many processes in the background. You have eliminated access to the user settings to be able to reduce that number. It is using so much memory (two tabs, one window, 1400 MB) it is becoming a nuisance rather than an asset. How do I reduce the number of processes. Thanks

There is a similar (but not identical) topic on Mozilla Connect , and I posted there. But I did not get a response. So I am re-posting on this new topic on Mozilla Support. I have a similar problem to what was discussed on Connect. I am using Firefox 133.0.3 on Windows 10 Professional. After Firefox has been running for a while, I get a message from Windows 10 that the free space on my C:drive is low. I did a directory listing on my C-drive before and after Exiting Firefox; I saw no large files disappearing. Then I decided to do "dir c:\ /ah" to see hidden files. What I saw was that pagefile.sys decreased in size from 29,925,748,736 to 16,270,770,176. This was a decrease of 13.7 Gb. Is this normal? I have lots of windows and tabs open in Firefox. Thanks.

Hi, after update 137.0.1 (64-bit) using Firefox with latest Gecko driver 0.36.0 in Python Selenium stalls and fails to initiate drivers without returning initiation errors every second launch, previously this stall without returning initiation errors would happen every ~25th launch. Also when it does successfully launches previously 9 instances used to use about 95% of my 8 GB RAM, now 6 instances use 100% RAM. Nothing else in my system changed besides Firefox update.

For little more than year I've been battling with an issue, where after watching Youtube for hour or two, and having 5-6 open tabs with videos, at some point Firefox would crawl to a stop with UI going down to 1-2 fps, and finally inability to click anything, until I restarted the browser.

Only today I have pieced together, that when it happens, task manager shows almost all of my GPU's VRAM (Dedicated GPU memory) is claimed by Firefox. It looks that there is a GPU memory leak somewhere.

How should I go on about this? If it's a bug, what I should include in a report?

Here is ~2 hrs of progress, PC and Firefox specs at the end:

This is after watching one ~20 minute video:

====================

GPU (pid 10124) Explicit Allocations

0.24 MB (100.0%) -- explicit └──0.24 MB (100.0%) -- gfx/webrender/gpu-cache

  ├──0.24 MB (100.0%) ── metadata
  └──0.00 MB (00.00%) ── cpu-mirror

Other Measurements

0.78 MB (100.0%) -- gfx └──0.78 MB (100.0%) ── webrender/textures/gpu-cache

 265.84 MB ── gpu-committed

1,246.20 MB ── gpu-dedicated

  11.72 MB ── gpu-shared

End of GPU (pid 10124)

====================

After second video, another 15 minutes later:

====================

GPU (pid 10124) Explicit Allocations

0.29 MB (100.0%) -- explicit └──0.29 MB (100.0%) -- gfx/webrender/gpu-cache

  ├──0.29 MB (100.0%) ── metadata
  └──0.00 MB (00.00%) ── cpu-mirror

Other Measurements

0.63 MB (100.0%) -- gfx └──0.63 MB (100.0%) ── webrender/textures/gpu-cache

 277.34 MB ── gpu-committed

1,737.74 MB ── gpu-dedicated

  16.55 MB ── gpu-shared

End of GPU (pid 10124)

====================

After opening and CLOSING several youtube tabs, withplaying 10-15 seconds of each video:

====================

GPU (pid 10124) Explicit Allocations

0.19 MB (100.0%) -- explicit └──0.19 MB (100.0%) -- gfx/webrender/gpu-cache

  ├──0.19 MB (100.0%) ── metadata
  └──0.00 MB (00.00%) ── cpu-mirror

Other Measurements

0.78 MB (100.0%) -- gfx └──0.78 MB (100.0%) ── webrender/textures/gpu-cache

 390.18 MB ── gpu-committed

4,339.20 MB ── gpu-dedicated

   4.27 MB ── gpu-shared

End of GPU (pid 10124)

================================

Here, I closed all tabs except about:memory. After another ~60 minutes of random browsing non-video pages (literally text pages and Google Docs):

====================

GPU (pid 10124) Explicit Allocations

0.25 MB (100.0%) -- explicit └──0.25 MB (100.0%) -- gfx/webrender/gpu-cache

  ├──0.25 MB (100.0%) ── metadata
  └──0.00 MB (00.00%) ── cpu-mirror

Other Measurements

0.94 MB (100.0%) -- gfx └──0.94 MB (100.0%) ── webrender/textures/gpu-cache

 324.99 MB ── gpu-committed

4,396.21 MB ── gpu-dedicated

   0.62 MB ── gpu-shared

End of GPU (pid 10124)

====================

It never goes down.

Then, I opened played for few seconds, stopped and closed (including tabs) ~15 youtube videos:

================================

GPU (pid 10124) Explicit Allocations

52.08 MB (100.0%) -- explicit ├──23.07 MB (44.29%) -- gfx │ ├──23.07 MB (44.29%) -- webrender │ │ ├──10.00 MB (19.20%) ── upload-stagin-memory │ │ ├───6.74 MB (12.95%) ── texture-cache/structures │ │ ├───3.69 MB (07.08%) -- interning │ │ │ ├──1.48 MB (02.84%) -- clip │ │ │ │ ├──0.78 MB (01.50%) ── interners │ │ │ │ └──0.70 MB (01.34%) ── data-stores │ │ │ ├──1.24 MB (02.39%) -- text_run │ │ │ │ ├──0.92 MB (01.77%) ── interners │ │ │ │ └──0.32 MB (00.62%) ── data-stores │ │ │ └──0.96 MB (01.85%) ++ (15 tiny) │ │ ├───0.95 MB (01.83%) ++ (6 tiny) │ │ ├───0.89 MB (01.71%) ── shader-cache │ │ └───0.79 MB (01.52%) -- resource-cache │ │ ├──0.79 MB (01.52%) ── fonts │ │ └──0.00 MB (00.00%) ++ (3 tiny) │ └───0.00 MB (00.00%) ++ (3 tiny) ├──19.94 MB (38.30%) ── heap-unclassified ├───4.00 MB (07.68%) ── ac2d/heap-resources ├───3.25 MB (06.25%) -- threads │ ├──2.29 MB (04.40%) ++ stacks │ └──0.96 MB (01.85%) -- overhead │ ├──0.91 MB (01.76%) ── kernel │ └──0.05 MB (00.09%) ++ (2 tiny) ├───1.35 MB (02.59%) -- phc │ ├──1.35 MB (02.59%) ── metadata │ └──0.00 MB (00.00%) ── fragmentation └───0.46 MB (00.89%) ++ (9 tiny)

Other Measurements

134,217,727.94 MB (100.0%) -- address-space ├──132,114,625.34 MB (98.43%) ── free(segments=370) ├────2,101,793.05 MB (01.57%) -- reserved │ ├──2,097,077.34 MB (01.56%) ── mapped(segments=14) │ └──────4,715.70 MB (00.00%) ── private(segments=550) └────────1,309.55 MB (00.00%) ++ commit

72.73 MB (100.0%) -- decommitted └──72.73 MB (100.0%) -- heap

  ├──61.39 MB (84.41%) ── decommitted
  └──11.34 MB (15.59%) -- unused-pages
     ├──11.34 MB (15.59%) ── fresh
     └───0.00 MB (00.00%) ── madvised

304.62 MB (100.0%) -- gfx └──304.62 MB (100.0%) -- webrender

  ├──302.79 MB (99.40%) -- textures
  │  ├──192.00 MB (63.03%) ── render-targets
  │  ├───44.00 MB (14.44%) -- texture-cache
  │  │   ├──44.00 MB (14.44%) ── atlas
  │  │   └───0.00 MB (00.00%) ── standalone
  │  ├───32.00 MB (10.51%) ── depth-targets
  │  ├───18.93 MB (06.21%) ── swap-chains
  │  ├───11.25 MB (03.69%) ── upload-staging-textures
  │  └────4.61 MB (01.51%) ++ (5 tiny)
  └────1.83 MB (00.60%) ++ images/mapped_from_owner

128.00 MB (100.0%) -- heap ├───72.73 MB (56.82%) -- decommitted │ ├──61.39 MB (47.96%) ── unmapped │ └──11.34 MB (08.86%) -- unused-pages │ ├──11.34 MB (08.86%) ── fresh │ └───0.00 MB (00.00%) ── madvised └───55.27 MB (43.18%) -- committed

   ├──48.27 MB (37.71%) ── allocated
   ├───3.95 MB (03.09%) -- bin-unused
   │   ├──2.35 MB (01.84%) ++ (44 tiny)
   │   └──1.60 MB (01.25%) ── bin-1024
   ├───1.96 MB (01.53%) ── bookkeeping
   └───1.09 MB (00.85%) ── unused-pages/dirty

41 (100.0%) -- ipc-channels ├───7 (17.07%) ── PCompositorManagerParent ├───7 (17.07%) ── PImageBridgeParent ├───7 (17.07%) ── PVRManagerParent ├───6 (14.63%) ── PRemoteDecoderManagerParent ├───5 (12.20%) ── PAPZInputBridgeParent ├───4 (09.76%) ── PCanvasManagerParent ├───2 (04.88%) ── PVideoBridgeParent ├───1 (02.44%) ── PGPUParent ├───1 (02.44%) ── PProfilerChild └───1 (02.44%) ── PVsyncBridgeParent

78 (100.0%) -- ipc-channels-peak ├──14 (17.95%) ── PCompositorManagerParent ├──14 (17.95%) ── PImageBridgeParent ├──14 (17.95%) ── PVRManagerParent ├──13 (16.67%) ── PRemoteDecoderManagerParent ├──10 (12.82%) ── PCanvasManagerParent ├───8 (10.26%) ── PAPZInputBridgeParent ├───2 (02.56%) ── PVideoBridgeParent ├───1 (01.28%) ── PGPUParent ├───1 (01.28%) ── PProfilerChild └───1 (01.28%) ── PVsyncBridgeParent

25 (100.0%) -- observer-service └──25 (100.0%) -- referent

  ├──22 (88.00%) ── strong
  └───3 (12.00%) -- weak
      ├──3 (12.00%) ── alive
      └──0 (00.00%) ── dead

1 (100.0%) -- preference-service └──1 (100.0%) -- referent

  ├──1 (100.0%) ── strong
  └──0 (00.00%) ++ weak

               1 ── ac2d-context-count
               0 ── ac2d-target-count
         4.00 MB ── ac2d-texture-memory
         0.00 MB ── gfx-d2d-vram-draw-target
         0.00 MB ── gfx-d2d-vram-source-surface
       462.87 MB ── gpu-committed
     6,829.63 MB ── gpu-dedicated
         0.62 MB ── gpu-shared
        48.27 MB ── heap-allocated
         1.00 MB ── heap-chunksize
       686.68 MB ── private
       558.20 MB ── resident
       481.14 MB ── resident-unique
        44.44 MB ── system-heap-allocated
 2,103,102.59 MB ── vsize

129,414,503.44 MB ── vsize-max-contiguous

               0 ── webgl-buffer-count
         0.00 MB ── webgl-buffer-memory
               0 ── webgl-context-count
               0 ── webgl-renderbuffer-count
         0.00 MB ── webgl-renderbuffer-memory
               0 ── webgl-shader-count
               0 ── webgl-texture-count
         0.00 MB ── webgl-texture-memory

End of GPU (pid 10124)

====================

This just continues, when gpu-dedicated hits ~7.8 GB, Firefox becomes unusable, and rest of the system appears a bit sluggish.

I can't say if this is regression, since I haven't been watching YT at all until recently.

Windows 10 Pro 22H2 Firefox Nightly 64 bit EN, 139.0a1 build 20250405211119 Checked in my normal everyday profile and with new clean one. GPU acceleration enabled, all video codecs installed.

Hardware: Core i7 9750H, 32 GB DDR4, GeForce 4060 8 GB. this is NOT a RAM issue, RAM usage never goes above ~19 GB on this PC.

It happens a tad bit slower than before, when I had 1060 6 GB.

I also noticed it on my laptop with integrated Intel GPU, but I don't have it anymore, so can't really check.

Even with all media tabs closed, GPU process keeps hogging memory. Tried with extensions disabled, but no effect. The main culprit is this GPU process. screenshot attached.

For some weeks I have ad an issue with Firefox using 50%-100% of CPU. Normally it is the Firefox process itself, sometimes it is also "Privileged Cont".

OS is Kubuntu 24.04. Firefox has done this across 2-3 versions.

Things I have tried:

Restarting Firefox No change, I'll even get 100% cpu usage with no tabs open

Refresh Firefox to remove settings and addons No change

Uninstall Snap and try direct Apt package No change

Remove ~/.mozilla to fully remove any residual settings/cache/etc No change

Try with and without hardware acceleration See: https://support.mozilla.org/en-US/questions/1308215 No change!

I would blame my old computer hardware, but Brave runs fine. I am now using Brave, but would dearly like to return to Firefox as I miss containers, and I don't support a chromium dominated web.

Please assist or advise why Firefox seems to be slowing down my system by memory usage. I have a handful (6) of tabs open on 1 browser session and my system started slowing down so I checked my task manager and it shows that I have more than a dozen of Firefox instances open chewing up almost 90% of my memory.

Please assist or advise me on how to tweak my browser to perform better, and not to show ghost instances

I'm finding that firefoxcp isolated web content uses a LOT of memory on my Mac Mini. What can I do about this besides not using Firefox. I like the browser and have been using it since its introduction

Unable to watch on YT ESL spirit v EF CS2 as memory usage constantly going up until pc almost locks up. Had this issue a few weeks back and it was the chat however now disabling chat makes no difference.

Nm tried disabling Ublock origin and it's fixed, left this there as it might be useful to you guys

I can only use firefox for 90 minutes at a time, before the entire system crashes.

Since the last couple of updates, the infamous memory leak issue has gotten significantly worse. Now 30 minutes of use with no add-ons sees the memory use swell to 13 GB, crashing the system. Sometimes windows 10 crashes, sometimes it just kills firefox.

The thing is, when I check about:memory, it says firefox is only using 1.5 GB. However task manager says 13 GB, and if I close the browser, suddenly 13 GB memory gets freed up.

Does anyone have any idea why there's such a discrepancy?