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Multiple Firefox Instances

It can often be useful to have multiple Firefox browsers open at the same time. Particularly for testing web sites or any sort of web development. Or even just so you can be logged into two sites at the same time with different accounts.

Firefox provides such a feature with the -no-remote switch. The first step is to create multiple Firefox profiles. To do this, launch Firefox with the -ProfileManager switch.

On Windows click Start > Run then:

"C:\Program Files\Mozilla Firefox\firefox.exe" -no-remote -ProfileManager

On *nix launch the command:

firefox -ProfileManager

Then create a new profile. If you want to make a copy of your existing profile, simply create the new profile, then copy the current profile directory to the new profile directory.

Now you’re ready to launch Firefox with the -no-remote switch. The trick is that you need to select your second profile when you launch your second instance. So start Firefox as normal, then launch a second browser.

On Windows click Start > Run then:

"C:\Program Files\Mozilla Firefox\firefox.exe" -no-remote -P "secondprofilename"

On *nix launch the command:

firefox -no-remote -P secondprofilename<br />

Bingo, now you should have two separate Firefox windows, each running independently of each other. If you click on links in another program, they will probably go whichever Firefox window you opened first. Enjoy. More info.

Comments

thunderror at 2008-08-03 00:32:25

Just what I was looking for. I added the no-remote switch and now it works, only problem is, it still continues to load the already loaded profile in the second instance as well...

dano at 2012-01-26 21:21:04

I figured out to control how Ubuntu launches URLs. In Preferences-&gt;Main Menu-&gt;Internet the "Firefox Web Browser" that was put there by the system determines how Ubuntu launches URLs. I changed it to xterm and clicking a link opens an xterm. You can rename and move that item, and it still performs the same function. So you do not want to change the command for that one. What I did was change the name of that one to "Firefox (preferred application)", changed the icon, and moved it further down the list. I added a new entry called "Firefox" and set the command to "start_firefox -P default %u". Now everything is working like it used to work.

Callum at 2008-08-04 12:23:43

@<a href=http://www.callum-macdonald.com/faq/multiple-firefox-instances/#comment-28335" rel="nofollow">thunderror</a>: I'm not sure what you mean. It should load different profiles in each instance. As far as I'm aware, you can't load the same profile in two instances simultaneously.

Firefox Blog at 2009-04-26 00:31:51

<strong>Utilizzare più profili di Firefox allo stesso tempo...</strong> Sapevi che è possibile eseguire più di un profilo di Firefox in una sola volta? Questo può essere estremamente utile se si vogliono testare le estensioni più facilmente, creare un profilo di sviluppo web, eseguire un profilo snellito solo per Gmail...

Bob W at 2009-04-02 04:56:37

Very helpful, works like a charm. A second instance of Firefox in my startup menu now opens Craigslist searches for all items I'm patiently waiting to find at bargain prices...

Sarah at 2011-02-18 10:56:16

Whenever I do this and try to open both profiles I get a message that says "Firefox is already running, but is not responding. To open a new window, you must first close the existing Firefox process, or restart your system."

Callum at 2012-01-08 17:55:06

I'm not a windows user, so I'm not sure how you'd create the shortcut, but I'm sure it's possible. Glad the writeup was useful. :-)

Callum at 2011-06-09 12:31:37

Personally, no idea. I just tested on Ubuntu and I see the same behaviour, two windows open, one private one normal. If you want to browse private all the time, you could create a profile specifically for that and turn off everything (kill cookies, history, etc, etc). I'm not very familiar with private browsing, but I think it would come to the same thing.

Gilles at 2011-10-20 13:30:56

Thx alot, been searching for that info, methods old tutos don't work in 7.1. This seems to work for now :)

smaramba at 2011-03-04 11:34:45

I'm a linux user like Callum, but if memory serves me well, try to search for 'run' in the start menu. it should be the topmost result.

Всем привет, aka Hello world! | My WebDevel blog at 2010-07-09 08:37:44

[...] Multiple Firefox Instances &#8211; просто и понятно. а я смотрю &#8211; у меня в запуске стоит &#8220;firefox -no-remote -ProfileManager&#8221; &#8211; начал выяснять. Пускать параллельно разные профайлы надо оказывается так: &#8220;firefox.exe&#8221; -no-remote -P &#8220;secondprofilename&#8220;. то что надо. на ту же тему How to run different Firefox profiles at the same time [...]

dano at 2012-01-11 23:41:30

I'm still running Ubuntu 11.04 (I HATE Unity), and my Firefox is version 8.0. I'm guessing the update to 8.0 is when the problem showed up.

Callum at 2012-01-11 23:46:51

Likewise, I'm really not a fan of Unity. I like the ideas, but in 12.04 alpha, much of it is still pretty ropey. The run dialog, for example, don't even get me started! I didn't notice this behaviour before upgrading, and I'm pretty sure I was running FF 8 or higher. It could be tested in a VM running an older Ubuntu / Firefox, see if it arises at a certain point. Does the same behaviour occur if only one instance is running?

dano at 2012-01-12 00:07:28

The biggest problem for me with unity is the switch to application focus instead of task focus. For my job, I have 10 workspaces and I usually have 30 or more terminals open, 1-4 per task I am working on. With Unity (and gnome 3) all the terminals are combined into one and I cannot keep track of what I am doing. The error does happen with only one firefox open.

led at 2010-09-20 01:10:50

Is ProfileManager a program I need to download?

Callum at 2010-09-20 03:48:11

No.

Callum at 2011-02-18 17:47:02

That sounds like the --no-remote flag is not working properly. Try searching for <a href="https://duckduckgo.com/?q=firefox+no-remote" title="DuckDuckGo searchfor firefox no-remote" rel="nofollow">firefox --no-remote</a>, that might turn up some answers.

Jani "robsku" Saksa at 2010-08-25 20:16:02

Thanks, I was actually searching a way to launch firefox instance from remote system (on Linux through SSH connection with X Windows forwarding) but when I had firefox already running locally it would detect firefox running on same display and made remote call to the locally running instance and just open new window (or profilemanager of local systems firefox if that parameter was used. I already knew -ProfileManager but what really helped me in your article was the no-remote parameter. Thank you!

Setting Up a Clean Firefox Profile : touchground.com at 2010-03-10 10:11:11

[...] http://www.callum-macdonald.com/about/faq/multiple-firefox-instances/ [...]

Usman at 2012-01-08 17:53:04

Thank you for the amazing tutorial. I really needed this. Is this possible to add the shortcut to the desktop instead of doing this every time? On Windows click Start &gt; Run then: "C:\Program Files\Mozilla Firefox\firefox.exe" -no-remote -P "secondprofilename"

Callum at 2011-12-01 00:19:54

No. Each instance needs a separate profile because you can't have two sets of session cookies, etc in the same profile.

Usman at 2012-01-08 18:22:58

Yeah It is possible. Actually this was mentioned in the link which you provided. So I would like you to thank you again. :) http://kb.mozillazine.org/Command_line_arguments "If you regularly wish to start your application using command line arguments then you can also create a shortcut on your Desktop which includes them. To do this, right-click on an open space of the desktop and choose "New -&gt; Shortcut". Follow the wizard to create the new shortcut. When it prompts you for location (not name), type the file path and file name followed by the command line arguments, exactly as in the example above. "

Raju at 2011-11-30 23:44:39

Can you create two instances of Firefox without creating two profiles? Currently if i open a website with two instances of Firefox, the contents generally merge. however if i create two profiles then it works fine.

Tremble Before Me at 2011-04-18 00:08:11

This is sweet, I was trying to follow earlier instructions from others where the profile manager was a separate executable file, your info on the program switches was what I needed. This is vital to run two accounts with two different names in the same game, since cookies are saved to get you into the right account... Thanks for your help.l

omkar at 2013-02-19 16:29:16

as per your suggestion instead of using import from chrome i went to import from HTML file so now it has nothing to do with chrome exporter .Still got the same result :(

Callum at 2013-02-19 16:36:22

Strange, my bookmarks are definitely separate, but I've never imported them. If you manually delete from one profile does it also delete on the other?

dano at 2012-01-11 23:31:31

I've been using this for years on Ubuntu. Until recently, clicking a link in Evolution or using "Open Link" from a right click on an URL opened the page in the first Firefox that I opened. Recently, in the past month or so, I get the "Firefox is already running, but not responding" error. My setup is unchanged, but Firefox has been updated. Anyone else see this? Anyone found a workaround? Thanks!

Callum at 2012-01-11 23:34:47

I have noticed the very same thing in the last couple of days since I upgraded to Precise (12.04). I wonder if it's a bug in the new version of Firefox, I'm now on 10.0 since upgrading. If you find a solution, please do post it here or let me know. I'll do likewise. No doubt at some point (once I iron out the other bugs!) I'll get round to look into into it. :-)

Sarah at 2011-02-21 13:12:42

It's fixed now. I had a two name profile name set up, deleted it, and made a new one with the same name, but no space inbetween the names. Looks like if the profile has two words in it, they need to have an underscore between them like Jane_Doe and it is case sensitive.

Callum at 2011-02-21 13:16:48

I think profile names are case sensitive, and spaces are probably ok, but you'd need to surround the name in quotes when you run the command, so you'd run <code>firefox --no-remote -P "profile name"</code>. Either way, it's always simpler to use underscores, that avoids all the hassles. :-)

John at 2010-12-04 16:03:29

I was looking for this info thanks a bunch

Rick at 2011-04-21 12:04:20

I've been using a similar command for some time but with the added option of -private e.g start "" "C:\Program Files\Mozilla Firefox\firefox.exe" -private -no-remote -P Myprofile This worked fine on firefox 3.6.... one firefox session would open in private mode However..... on firefox 4.0 two sections of the same profile would open, one normal and one private ? Any ideas, I guess this is a bug in firefox4? Cheers R

Nick @ ionCube at 2011-03-09 13:25:37

Thanks, works a treat for multiple profiles.

Morgan Roderick at 2011-05-11 11:41:24

Still works like a charm. I am now running Firefox 3.6.17, Firefox 4.0.1 and Firefox Nightly at the same time on my Win 7 VM. Thanks for sharing :-)

ahmet at 2011-02-27 15:43:15

Hi callum pls can you tell me how to install this on windows 7 it worked fine at vista but couldnt fix it with windows 7 ... Thank you for the advices sincearly

Callum at 2011-02-27 15:57:00

I have no idea about Windows, I haven't used Windows for years and I'm glad to have never owned a Windows Vista or 7 computer. :-) As far as I'm aware, you really don't need to install anything, it's just part of Firefox automatically. But to be honest, on Windows, you're on your own, I focus my support energy on GNU/Linux users.

ahmet at 2011-02-27 17:13:46

On Windows click Start &gt; Run then: "C:\Program Files\Mozilla Firefox\firefox.exe" -no-remote -ProfileManager Hi again sorry but just wonder how i can do this on windows 7 ,dont know how to do that dont have run option on windows 7. Tried to past it to command but didnt work Thank you again for your answer

Callum at 2011-03-04 11:37:18

Oh, and you could try pressing the WindowsKey - R, that used to work on older versions of Windows.

Callum at 2012-05-09 13:34:42

You could try with single or double dashes, I think officially it's <code>`firefox -no-remote`</code> but I always use <code>`firefox --no-remote`</code> instead.

mosco at 2012-01-29 19:01:24

Comment revenir a une monoséssion ? j'ai supprimé les sessions supprimer FF, ré installer et j'ai toujours pour la seconde session "Firefox est déjà en cours d'exécution mais ne répond pas. Pour ouvrir une nouvelle fenêtre, vous devez d'abord arrêter le processus Firefox existant ou redémarrer votre système."

ahmet at 2011-03-01 09:09:45

Fix that problem ::)) thank you

PanAeon at 2012-04-12 09:26:50

Thank you, sir! Works like charm!

Riccardo at 2011-09-27 11:43:40

It works great in indows 7 but i want to call an imacro from command line,one for profile 1 and another for profile 2.For the first profile its ok but for the second profile it doesn t work

Callum at 2011-04-24 11:07:32

Not sure, maybe the flag changed for private browsing in FF4. Does Firefox load as expected without the -private flag on FF4? I'm really not an expert, not sure what to suggest.

jon ludlum at 2011-01-18 21:49:58

ok, working good. is there a way to make shortcuts for version 3.6 for both accounts to make it easier to get into?

Callum at 2011-01-19 07:34:06

On which operating system?

DAW at 2011-01-21 21:54:05

Very helpful. Thanks for posting this!

Callum at 2012-05-24 22:42:18

I have no experience of multifox and this is my personal site, not a professional support site. I recommend trying other places or forums for help.

gvf at 2011-02-23 17:50:50

Thank you man, that is I was looking for. Suits perfect!

Stu at 2011-03-19 08:21:00

Windows 7... in the Start Menu Program search box type "Run", select Run from the list, then "firefox.exe -no-remote -profilemanager"

Andrew at 2011-07-28 02:40:55

I'm so glad I found this ability. I like the idea of separating my private browsing windows from my non-private browsing windows. The one thing that Google Chrome does well. Callum, your tutorial lets me do exactly what I wanted. Thanks again

Confused and Not techy at 2012-05-24 20:03:21

Hello. I would love to run this but I have four accounts hooked up through Multifox. I also have no experience comp wise. Could you run me through a step by step thru video or something please? Many thanks. Confused and Not Techy

Kainsmoney at 2011-03-28 04:47:47

Thanks buddy, i am using Auto surf programs, and the ram goes up at 1gb ram with easy, need another instance to run small stuffs which does not eat that much and i have enough ram to run more profiles.

R Srinivasan at 2012-03-19 18:06:10

Is there any ways to share bookmarks between multi-profile firefox instances. Thanks.

slicnick at 2011-09-29 19:25:41

i have greasemonkey on my first account, but it's not letting me download it on my 2nd account...

Saevar Einarsson at 2012-02-06 19:58:16

On Windows x64 the command is "C:\Program Files (x86)\Mozilla Firefox\firefox.exe" -no-remote -ProfileManager

Maki at 2011-12-19 12:06:41

Awesome tutorial! It's amazing what (undocumented) commandline options exist to make life for people like us a teensy tiny bit easier. :p Thanks to you, I now run a proxied and unproxied FF instance on my main PC without a problem, where earlier I had to look at alternatives to FF to do so. (F*** Chrome, Opera or IE... they really really don't work for me.) You're a lifesaver. ^-^

Vic at 2011-06-09 00:20:30

Any updates on this one? I have the same problem: "...-P secondprofile -private" opens one normal and one private window. Need to get rid of the normal window on startup Other than that, fabulous info. Thank you Linux guys :) (Win7)

Tired of Different Online Identities Following you Around? &laquo; Ryanph at 2012-08-10 19:20:00

[...] two IE&#8217;s or Tabs using different Identities.  To use more multipleidentities you can use This article, which explains how you can use Firefox to set up infinite sessions using separate [...]

dano at 2012-01-19 17:35:44

I wrote a little script to work around the problem. Save the script somewhere in your PATH as start_firefox. Then change your menus to call start_firefox instead of firefox and remove the -no-remote. For example: start_firefox -P work %u Here is the script: #!/bin/sh running=`pgrep -x firefox` if [ -n "$running" ]; then firefox -no-remote $@ &amp; else firefox $@ &amp; fi

Callum at 2013-02-19 16:13:19

Have you maybe enabled sync? My bookmarks are definitely separate between the separate profiles.

omkar at 2013-02-19 16:17:00

i have never set sync . Is it enabled by default ?

Callum at 2013-02-19 16:18:44

I don't think so, no. Very strange, not sure what's going on. Maybe something funky with the importer. You could try exporting and importing again, maybe the chrome importer puts the bookmarks in all profiles, but another import / export does not?

omkar at 2013-02-19 16:07:04

hii its really working , thanks for the helping article . i have 1 doubt - i have 2 profiles say A and B i want to import my bookmarks from chrome to profile A ONLY . so i tried to do that by opening firefox in profile A and following Import bookmark procedure , but it also allows B to see those bookmarks . Is their any way to restrict profile B from accessing / seeing those bookmarks ?

Ven Koneru at 2012-02-23 16:06:23

Callum, You are genius. Gave a perfect solution for my problem. Not many people know about this. Thanks. I wish there is a Like button. However, I share this link with my circles and friends.

byg at 2013-02-10 15:33:11

Finally!!!!! Was looking for this for the past 2 years...

omkar at 2013-02-19 19:17:56

yes its deleting bookmarks from other profile also

TK at 2011-09-07 08:15:52

I have it working now. Awesome, thanks so much for this.

TK at 2011-09-07 08:09:42

Thank you for the reply. I think I am having trouble with greasemonkey in general. I am going to try using scriptish instead and see how it goes. Thanks again for the info on how to do this.

Firefox and the release channels &#10025; Mozilla Hacks &#8211; the Web developer blog at 2012-05-08 10:16:31

[...] option, in plain code and as outlined in Multiple Firefox Instances, is to just launch the Profile manager directly: # On Windows click Start &gt; Run then: [...]

Callum at 2011-09-06 11:34:37

I can add that greasemonkey works fine for me in multiple profiles in every version of Firefox since 3.x.

Callum at 2011-09-06 11:33:58

If you're asking me, I have no idea. Perhaps somebody else will see your question and reply, but somehow I doubt it, this is not a very popular blog post. :-)

TK at 2011-09-06 07:09:45

Hi, I tried this with cometbird browser which is also made mozilla and it worked great. I need to know if there is a way to be able to use greasemonkey and user scripts in the second instance of the browser. Everything seems to work fine except for that. Please let me know, I even installed greasemonkey and the scripts on the second instance and they just don't do anything. Thank you.

M Nabeel Imran at 2012-04-26 15:59:53

Done! Thanks :-)

Callum at 2012-01-21 16:25:09

Interesting. I've done some experimenting. Calling <code>`firefox http://url/`</code> will always open a new tab with the link. However, when the first firefox instance is started with --no-remote, clicking a link appears to launch <code>`firefox --no-remote http://url/`</code> which will not work. The --no-remote flag cannot be used with a url if firefox is already running. I'd guess this bug lies somewhere with Ubuntu's method of sending urls, but that's something I know nothing about. Maybe there's a way to modify that. Thanks for posting your script. I'll start firefox without --no-remote for the first profile by hand, I always start it from the run prompt anyway. Good to know there is a solution, thank you kindly.

Callum at 2012-04-26 13:49:06

I copied and modified a <code>.desktop</code> file from <code>/usr/share/applications/</code> to <code>~/.local/share/applications/</code> and it worked for me, but it's not something I'm particularly familiar with.

M Nabeel Imran at 2012-04-26 13:44:07

Hello! Thank you for the wonderful tip :-) Can you guide me how to make a .desktop shortcut for each profile? I use Arch x86_64 with GNOME

MattK at 2011-11-07 22:46:16

Strangely the new profiles cannot access https sites. Other sites work fine but https fails for some reason.

Tsui at 2012-08-31 05:36:47

Thank you very much for your useful, accurate, easy-to-use instructions!

Callum at 2012-03-20 17:44:50

You could use some kind of bookmark sync service. Firefox ships with such a service I believe. I'd imagine it could be configured to keep multiple profiles in sync, but it's not something I've personally experimented with.

Jason at 2012-04-26 21:58:50

I did the run and everything but it keeps telling me that it is miss spelled and to try again. Any ideas?

salvador sciabica at 2011-09-01 03:24:21

mira a mi no me hace nada me dice no se encuentra ningun elemento coincidente lo con el criterios de busqueda. que puedo hacer?

Mozilla Hacks Weekly, May 3rd 2012 &#10025; Mozilla Hacks &#8211; the Web developer blog at 2012-05-03 08:59:03

[...] Multiple Firefox Instances [...]

Callum at 2013-02-20 13:46:30

Strange, not sure what's going on there. I'm on Ubuntu and my profiles are 100% separate. Best of luck finding a solution.

Adam at 2012-06-22 09:09:10

ahh, tyvm for the information. I was looking at several solutions to this problem that involved using other programs, but this method is much better. note for windows 7 (I'm pretty sure this works in Vista too) users: You don't need the run box for this; simply click on the start button and start typing (text will appear in the "Search Programs and Files" box at the bottom). You also do not need to include the full path. use this (without the " ") "firefox.exe -no-remote -profilemanager" to bring up the manager. create a new profile and name it. Then you can open it later, or create a shortcut, using "firefox.exe -no-remote -p nameofprofile", or just launch it from the profile manager itself using the first command.

ray at 2013-02-05 10:33:17

wow just wow, this trick has save me $75

Rohi at 2012-07-09 14:02:33

Thank you very much this is exactly what I was looking for

Guang at 2012-11-28 05:33:09

Hi Callum, why on windows we can launch duplicate firefox process without creating profile? I really want a way to launch duplicate firefox process without having to create new profile....

Wahyu at 2013-07-13 04:47:08

Thanks callum. Now I can run FF 21 and FF 22. I still need to run the old version because I installed roboform

Callum at 2013-01-13 12:43:33

As I understand it, that's not possible, because you can't have two distinct browser sessions writing to the same profile simultaneously.

Geoffrey Dow at 2013-06-10 03:40:48

That seems like an incredibly complicated way to set up the feature, but it worked (Linux Mint 13), and I am really grateful to have come upon this. So thank you! Geoff

Toon at 2013-12-23 18:19:32

Thanks for the good summary how to get multiple profiles running in Firefox. I tried this solution with the PortableApps.com version of Firefox. To get it working with the PortableApps launcher, I needed to copy the FirefoxPortable.ini to the folder where FirefoxPortable.exe resides. In the ini-file I added the -no-remote entry to the AdditionalParameters-attribute. Just thought I'd share this solution.

Callum at 2014-10-03 20:02:33

I believe you need both <code>-no-remote</code> and <code>-ProfileManager</code> if you already have one Firefox instance running.

Kevin at 2014-09-18 15:40:51

RedHat 6.5 and Firefox 32.0.1.

Callum at 2013-11-06 18:25:56

Don't know if there's a limit, can't imagine there is, but I really don't know...

Venu at 2013-11-06 10:16:19

Is there any limit in the number of firefox profiles that can be created? My issue is I am currently doing selenium webdriver automation in linux for a device. There are 50 devices of same kind and framework will pickup a device depending on availability. I need to by pass unsigned ssl pages. I am using firefox 14. I have implemented following but it is not consistent. everytime a device is chosen adds cer of device to the cert file in firefox profile but I am getting sec_error_bad_signature very frequently. So I started recreating cert file for every run. Now this is posing a problem if multiple devices are run at the same time. Hence I want to create separate firefox profile

AJ at 2014-09-23 02:43:43

Hi. I am having an issue with my firefox right now. I had it set up to where I could open multiple profiles of firefox at the same time, having the profile manager launch each time I double clicked the desktop icon, but now I can't get the profile manager to pop up if I currently have a window open. I have to completely close out my current window to get the profile manager to launch. I have went in and added the "-ProfileManager" to the target launch, but it still hasn't fixed it. Any suggestions as to how to get it to work right again?

Callum at 2014-09-18 01:03:04

Which operating system are you using? I found this behaviour to be totally consistent on Ubuntu and OSX. I'd have liked a way to send the link to whichever tab I wanted, but could never get it to work. I'm now seriously considering dumping Firefox because of it's inordinate CPU usage, so I may soon be a Chrom(ium|e) user.

Kevin at 2014-08-15 15:01:35

You said that new links "will probably go whichever Firefox window you opened first." I'm finding the opposite - new links go to either the most-recently used or the most-recently opened, I haven't figured out which. I would like for new links to go to the first opened -- any thoughts since the time of this article on how FF determines which instance to send a new link? Not sure if this makes a diff, but in my case, instead of using multiple profiles, I've been opening a new tab first, then sending that tab to a new window. This doesn't give me the auto-start that's described in this blog, but it gives me much more dynamic control - I only open as few or as many spinoff windows as I need today. But through it all, I want my first instance opened to be the "main" one to which external links are sent. Thanks for any thoughts.

pankaj at 2015-01-20 11:57:57

Firefox is already running but is not responding - Error Message Fix

How To Fix Sec_error_bad_signature Firefox 4 in Windows at 2015-01-21 14:22:40

[&#8230;] Multiple Firefox Instances | Callum Macdonald – Thanks for the good summary how to get multiple profiles running in Firefox. I tried this solution with the PortableApps.com version of Firefox&#8230;. [&#8230;]

How To Fix Sec_error_bad_signature With Firefox 3 in Windows at 2015-01-22 08:37:59

[&#8230;] Multiple Firefox Instances | Callum Macdonald – Thanks for the good summary how to get multiple profiles running in Firefox. I tried this solution with the PortableApps.com version of Firefox&#8230;. [&#8230;]

Manuel at 2015-01-23 10:17:38

Thank you!

Ricardo at 2016-06-13 17:46:17

This is legendary! Cheers dude

James at 2016-07-26 15:07:54

Although a bit dated: When you send a new tab to a new window you aren't opening a new instance; you just outsourced that one tab of the same instance. That's why your link goes to the most recent tab/window. If you go with the procedure described by the author, thus opening second and subsequent Firefoxes with special -no-remote parameter and new profiles as new instances then links you click will be opened in the first instance.

Marco Fioramonti at 2015-11-03 16:34:36

Thanks for this article. I already had 2 FF installations with selected versions. I installed a new version of FF on a different path but any firefox.exe in the 3 paths ran the latest version. I created a new profile and setup the links in order to choose the right profile. Thanks again.

J. Jackson at 2018-09-08 00:41:15

This is an old thread, but hope it is still monitored. I want to create an isolated firefox instance, where I can have a separate cache area as well memory. I would like to delete all browsing history and cookies from this instance when closing the browser without affecting my primary instance. I would use my main browser for routine tasks like email for example, but would use this isolated one for when just doing general browsing. SOooo many sites are piling on ads and cookies, and it seems that FB, TWT,Google, et al. are capturing your browsing, evening if not on their site. I have looked at TOR Browser, but the performance is awful. Any help or suggestions greatly appreciated.

Callum at 2018-09-09 19:52:40

By far the easiest way to do this is to use two browsers. For example, use Chrome for email and firefox for general browsing. Then tell Firefox to delete everything every time it closes. I use something like this setup with heavy separation of tasks between browsers.