Does disabling an extension(s) speed up FF?

[CrackTipe]

What I mean is, I have a few extensions that I use only once in a while and I keep them disabled until I need them. But there's no point to this if keeping them disabled is no different than keeping them enabled.

[Helico]

It totally depends on the extension, and how limited your computer is for ram. Most extensions only change settings within firefox and don't "do" anything actively, so all they do is take a little ram. However, some extensions process information on the page and do slow things down.
Types of extensions that slow things down: Greasemonkey, Linkification, Downloadhelper, Forecastfox, Siteadvisor.

[CrackTipe]

Gotcha, thanks.

[BernG]

Didn't you answer your own question? You keep them turned off until you need them and you're asking if they slow Firefox down.

That tells me you haven't noticed a difference. Since you don't see a difference, why worry?

[wellofsouls]

Didn't you answer your own question? You keep them turned off until you need them and you're asking if they slow Firefox down.

That tells me you haven't noticed a difference. Since you don't see a difference, why worry?

It's much more complicated than that. At times different extensions enabled at the same time can cause some conflicts with each other or with some other existing software in the system and completely eat up RAM and CPU cycles. For my system when both Digg Toolbar and Firebug are enabled, Firefox suddenly eats up all the CPU cycles for no reason.

Back to the OP's question, the rough answer is yes, since one extension disabled at the very least means less XUL loaded and rendered, thus faster speed. But the XUL overhead won't be noticeable in most cases, unless you have a LOT of extensions enabled all the time. But there are many other factors that are much more unpredictable and can have much bigger impact on performance. For example extensions like Firebug can eat up a lot of extra resource processing the web pages, and extensions like Digg Toolbar can make a web page loading much slower as it retrieves the digg info, and this can become a LOT more significant if you open a lot of tabs.

So in the end the answer depends on what kind of extensions you are using, do they have some conflicts with each other, do they have conflicts with certain web site you are viewing, and do you open a lot of tabs when browsing, and individual system setup, anti-virus and firewall software settings, etc. etc.

[kindofabuzz]

On my system, no addons = 1-2s firefox startup. with about 15 addons, 15-17s startup.