Re: firefox is slow and uses a lot of memory

From: Gary Jennejohn <>
Date: Sat, 03 Jul 2021 08:03:36 UTC
On Fri, 02 Jul 2021 20:03:04 +0000
"Poul-Henning Kamp" <> wrote:

> --------
> Craig Leres writes:
> > Starting with firefox 89 or so, I've found it starts using a LOT of 
> > memory and actually makes the system sluggish and causes momentary X 
> > freezes. I have 32G of ram/swap, is it reasonable for firefox to use 15G?  
> I noticed recently that firefox had started DNS's all bookmarks rather
> aggressively I found something under about:config which made it stop,
> (sorry cant remember which setting) but that made it at lot more workable
> for me.

Another possibility would be to enter about:networking#dns.  A button
"Clear DNS Cache" will appear.  Click on that and check whether that
reduces the amount of memory being used by firefox.

Gary Jennejohn