How to Downgrade from Firefox 4 to Firefox 3.6/3.5

by Venkat eswarlu on March 12, 2011

in Firefox,How to,tips and tricks

downgrading from Firefox 4 to 3.6 thumb How to Downgrade from Firefox 4 to Firefox 3.6/3.5

Having Firefox 4 RC released with Tab Management feature (Panorama) and supports latest technologies and web standards, if you’ve installed Firefox 4 RC/final over existing installed Firefox 3.6 version in your Computer you’ll be automatically upgraded to Firefox 4. If you want to revert back to Firefox 3.6 which is called downgrading, here is how to downgrade from Firefox 4 to Firefox 3.6 or earlier versions.

Why should I downgrade? one major reason is extensions worked in Firefox 3.6 may not be compatible with latest Firefox 4 version. No one wants to sacrifice his favorite extensions, if you’re one of those this article will be for you.

Downgrading from Firefox 4 to Firefox 3.6 or earlier versions

1. Visit Mozilla FTP Server in your browser.

2.  Open latest Firefox 3.6 version folder (currently Firefox 3.6.15)

3. Open “Win32” folder and further open “en-US“ folder.

4. Download Firefox setup and install in your Computer, you’ll be automatically downgraded to Firefox 3.6. x version.

To downgrade to Firefox 3.5.x  version, you can download and install latest version from here by choosing your Operating System and language.

If you want to use or stay on Firefox 3.6.x/3.5.x version forever disable update for Firefox from Tools>Options>Advanced>Update  uncheck for  Firefox under “Automatically check for Updates to”.


{ 20 comments… read them below or add one }

Diane March 25, 2011 at 5:15 pm

I dont like FF 4. Want to go back to my last version. If I follow this – will I keep all my settings? Passwords, bookmarks etc…?


Venkat March 30, 2011 at 10:48 am

Mostly Yes.


Vivian March 30, 2011 at 2:48 am

YESSSSS. Thanks for the instructions! I hate FF4 and so many of my addons are incompatible. Happy to have the old version back.


Diane March 30, 2011 at 12:51 pm

Thankyou! done and all is good.

I really did NOT like firefox 4… wish I knew what the look/feel was like before I accepted the upgrade.

sigh – I love firefox too!
Cheers for help


Don April 10, 2011 at 6:12 am

That’s it stay on a platform that will most likely not get anymore security updates. People need to get over their fear of change.


Keith June 1, 2011 at 11:56 pm


Your sentiments are fine as long as the newer version isn’t buggy and a memory hog. When FF comes out with cleanups to FF4 maybe I’ll make the switch. Right now I am going back and helping my daughter switch back. She has had so many FF crashes and so many websites that no longer load that it is unusable for her college studies.


steve July 12, 2011 at 4:35 pm

change?! are you serious. The thing does not work, this isn’t evolution it’s mutation. I’ve spent more time killing off firefox.exe to try and get my computer to unfreeze this last week than I have in the last 12 months. Firefox4.0 is rubbish, it is totally incompatible with windows xp.


DonmyButtcheeks April 14, 2011 at 8:08 pm

Change my a$s, when something keeps freezing and stuttering every damn 10 seconds they might want to work on it before releasing.


Max Smith April 16, 2011 at 1:35 am

Couldn’t agree more. Since I installed FF4, about 3 weeks ago, I’ve had to kill the process in task manager about half-a-dozen times.

With the exact same number of tabs open and more working plugins FF3.6.16 (.exe and plugin-container) uses less than 0.5 GB of RAM, FF4 was using almost 2GB. Looks like a memory leak again.

Stick with FF3.6.16 you’ll be happier.


mozeralla April 22, 2011 at 8:28 pm

Firefox 4 sucks because many features which firefox 3 had are gone by default and i need to google it and read tons of things and then do configure each accordingly to make them appear in firefox 4. they should release firefox 5 immediately alright.


marv-germany May 10, 2011 at 12:21 am

thanks for this “how to..”
i hate FF 4
now i got my FF 3.6 back again :D


Lisa Y. May 11, 2011 at 3:51 am

Thanks so much for these instructions. Absolutely hated Firefox 4 and some of my favorite websites don’t work in it, along with the plugins that don’t work. Really happy to be back with the familiar version :)


Peter Andersson May 13, 2011 at 10:33 am

Going back to 3,6 as I write, the 4,0 froze on me at least once a minute and also I didn’t particularly like the new layout. Just for comparision I did fifteen minutes in IE (not done that in years) and when that worked faster and smoother I realized I had to go back to 3,6.


Ted June 1, 2011 at 2:37 am

Quite a shock that ff4 uses 3 x the Ram/CPU that 3.6 did with all the same extensions. It is generally an excellent browser so probably they just need to iron out a few things in the new version. For now though I am downgrading.


N1kolaz June 3, 2011 at 9:14 am

Thanks, this is what Im needing !


luke June 9, 2011 at 7:28 pm

or go here for the lasted 3.6.x releases


Gary June 24, 2011 at 7:03 pm


@luke – thanks for the url.

@all I don’t care for the layout either. Wish there was a skin for the old. I keep clicking the wrong place for features I use a lot. I got upgraded by accident while working.



Kretek July 6, 2011 at 12:21 pm

Memory requirements of new FF versions are sick. My open tab set (about 50) in FF3.6 eats 280MB, generates <1% processor load and works fine. In FF4 it eats 320MB, generates 55% processor load and it doesn't work fluently. In FF5 (why is it 5? Shouldn't it be 4.1?) it consumes 560MB (insane!!!), fluency is a bit better, but I didn't even check CPU usage – I instantly downgraded to 3.6 and now I browse happily again :)


Wes August 22, 2011 at 6:33 am

addons that I use frequently are not compatible with FF 6.0. Hate that they change the position of interface elements with each upgrade that only seem to complicate things. i’ll stick with the version i know. thx for help.


jazz October 31, 2011 at 6:17 pm

thanks … i have to degrade from firefox 7 to firefox 6 …


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