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Firefox reacts slower and becomes sluggish quickly

  • 9 replies
  • 1 has this problem
  • 61 views
  • Last reply by sata

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A few weeks ago I noticed that browsing in Firefox started being slower / sluggish.

It usually happens in YouTube or Twitch, but can also happen while scrolling with the mouse in wikipedia for example.

Some examples: -When having a Twitch stream open, the stream is running fine, but when clicking and moving the volume slider on the player, it does not move smoothly, and with some delay. -When doing a bit more heavy browsing, sometimes a tab might get "stuck", for example, the twitch stream might start to buffer for a few seconds. I notice the buffering is not related to any bandwidth related issue. -Firefox reacts slower (or with a small delay) while moving between tabs, clicking on links, etc. This usually happens only after a few hours after launching and browsing with Firefox.

Most happen after a while since I launch Firefox. And by a while I mean maybe 2-3 hours, and I don't have a ton of tabs open. It becomes slower much, much faster than it used to in the past.

Now, sometimes it can take Firefox up to 30 seconds to close completely, before I can launch it again.

I had the same Extensions installed before these issues started happening.

I tried uninstalling Firefox completely, then manually deleting the remaining profile folder, and do a fresh install of the latest Firefox version.

I checked the Windows Task Manager, and it shows (14) processes under Firefox. Is this normal? I tried unticking the "Use recommended performance settings" and restarting Firefox, but it still reached (14) processes after a couple of minutes.


I am not sure if it is related to Firefox itself. My computer is 5 years old but functioning properly...

I did not check if similar issues happen on a different browser. I am just so used to Firefox.

I had a few weird bug in Windows 10, but those existed for a good while now, and are not similar to the ones I experience while browsing with Firefox. I didn't notice anything similar while watching video files in a Media Player.

I am not sure if it can be hardware related. All seem to be working properly...


I want to figure out what is causing this. If you need any more information let me know.

A few weeks ago I noticed that browsing in Firefox started being slower / sluggish. It usually happens in YouTube or Twitch, but can also happen while scrolling with the mouse in wikipedia for example. Some examples: -When having a Twitch stream open, the stream is running fine, but when clicking and moving the volume slider on the player, it does not move smoothly, and with some delay. -When doing a bit more heavy browsing, sometimes a tab might get "stuck", for example, the twitch stream might start to buffer for a few seconds. I notice the buffering is not related to any bandwidth related issue. -Firefox reacts slower (or with a small delay) while moving between tabs, clicking on links, etc. This usually happens only after a few hours after launching and browsing with Firefox. Most happen after a while since I launch Firefox. And by a while I mean maybe 2-3 hours, and I don't have a ton of tabs open. It becomes slower much, much faster than it used to in the past. Now, sometimes it can take Firefox up to 30 seconds to close completely, before I can launch it again. I had the same Extensions installed before these issues started happening. I tried uninstalling Firefox completely, then manually deleting the remaining profile folder, and do a fresh install of the latest Firefox version. I checked the Windows Task Manager, and it shows (14) processes under Firefox. Is this normal? I tried unticking the "Use recommended performance settings" and restarting Firefox, but it still reached (14) processes after a couple of minutes. I am not sure if it is related to Firefox itself. My computer is 5 years old but functioning properly... I did not check if similar issues happen on a different browser. I am just so used to Firefox. I had a few weird bug in Windows 10, but those existed for a good while now, and are not similar to the ones I experience while browsing with Firefox. I didn't notice anything similar while watching video files in a Media Player. I am not sure if it can be hardware related. All seem to be working properly... I want to figure out what is causing this. If you need any more information let me know.

All Replies (9)

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Thank you for the helpful links. I have browsed through the suggestions.

I have now tried running Firefox in Troubleshoot Mode, as well as disabling Hardware Acceleration.

I quickly experienced similar issues. Most noticeably, it was not as snappy and quick to react.

I then ran Chrome (which I had installed for a while, but rarely use), and the difference was definitely noticeable!

I am pretty sure that Firefox should not run as it does for me right now. I guess I just "got used" to it, but now I can definitely see there is some kind of problem.

I looked in the links and the only other thing I can try to do is to update my GPU drivers (but I did already ran FF with HW acceleration unticked).

I guess that uninstalling Firefox and then doing a fresh install did not do the trick...

Any idea what might be causing this?

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I have created a new profile and launched it in a new browser window.

I did not change any settings. Only opened a couple of tabs and tested it.

It responded quickly for a bit, but in less than a minute of browsing, I already felt it being less snappy and responsive. I closed it and relaunched, and the same thing happens. It felt smooth only for about a minute.

It also had that same weird issue with the volume slider on a twitch stream.

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sata67 said

I checked the Windows Task Manager, and it shows (14) processes under Firefox

More than one process is normal for the current Firefox. http://www.ghacks.net/2016/07/22/multi-process-firefox/

Multi-process Firefox is codenamed "e10s". https://wiki.mozilla.org/Firefox/multiprocess


Start Firefox using Troubleshoot(Safe) Mode {web link}

A small dialog should appear. Click Start In Troubleshoot(Safe) Mode (not Refresh). Is the problem still there?


Start your Computer in safe mode with network support. Then start Firefox. Try Secure websites. Is the problem still there?

Starting Any Computer In Safe Mode (web link) Free Online Encyclopedia

https://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/

https://www.digitalcitizen.life/4-ways-boot-safe-mode-windows-10/ +++++++++++++++++++++++++++++++++++++++++++++++ If the problem goes away with the computer in Safe Mode, the problem is with one of the other programs on the system.

As a test, disable your protection programs.

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Thank you for the reply.

I have tried the following:

Running Windows Memory Diagnostics (the default, standard test) - found no errors. Running "MemTest" program per their instructions, for 2 hours - found no errors.

Restart Windows in safe mode with networking and testing some websites there. I noticed similar things in Firefox. It was acting the same. Disabling my Anti Virus / Fire Wall program.

I did not try running Firefox in Troubleshoot(Safe) Mode *while Windows was in Safe Mode with networking*. I will if that is needed.


I should add that I have an issue with Windows itself, which I feel is related:

Whenever I open a folder (Windows Explorer) which contains clips / movie file types, it may take a couple of seconds to show them, even if the View is set to Details. But when I get it to play, it plays fine.

Sometimes when opening several windows explorer windows, OR when browsing Firefox for a few hours and it gets less responsive, then all of my Windows Explorer windows will disappear. Like Windows terminated that process.

I feel like something happened with some Update that Windows did... because this issue wasn't present a while ago.

Is there is someway I can check this issue specifically? Instead of doing new windows installation? I just don't want to through that hassle of a new installation.

Modified by sata

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I called for more help.

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You can do a malware scan just to be sure.

Is Firefox using a lot of memory when it behaves sluggish ?

You can check the Firefox Task Manager (about:performance) and about:memory and about:processes pages.

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After reading a bit about Windows Explorer - the process I believe is problematic, I tried a few things:

I opened command prompt and ran chkdsk on the system drive - it did not find any problems. I then ran sfc /scannow - when it finished, it wrote that it found corrupt files and successfully repaired them.

I also ticked the option "Launch Folder Windows in a Separate Process" as I read that that might help as well.

I used the built in Windows Defender AV to do a quick scan, and it did not find anything. I did not yet run any other anti-malware programs.

I then restarted my computer. Using Windows Explorer to browse pictures and videos, and now it feels much better. It is much smoother and does not take time to load information. I can definitely notice the difference.

I did not test for enough time, but so far, Firefox also feels snappier and quicker to respond than before. I can still notice some small weird quirks in certain sites, and I am not sure if that is just how it is, or if there is still a problem.


So, fixing the corrupted files (and maybe also ticking "Launch Folder Windows in a Separate") definitely helped, both with Windows and with Firefox.


Oh, and I forgot to mention: Now, Windows Task Manager shows under "Apps": Firefox (7), and not (14) processes like it did before I tried to solve the problem. But, I do have 6 *more* Firefox processes under "Background Processes" And I did not change the Performance settings in Firefox.

I have no idea if that is related to anything... it could be just how windows and Firefox handles things...

Modified by sata