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Does Private Browser save session data across Browser windows?

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  • Last reply by cor-el

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I've been struggling today with accessing two systems on my work laptop. As I'm an administrator on both sites, I've been purposely using "private mode" browser sessions in Firefox (my default and fav) but I was surprised to see that the private mode appears to be "save" some of the session data from those systems - at least temporarily until I close all of those windows entirely?

I log in to one of those corporate sites with a username + password, then attempt to login to the other one in a separate tab, but it immediately attempts to auto-login me in with the credentials from the first site (which doesn't work as both sites require a different username/password for security reasons). I tried several combinations: I used separate private browser windows (instead of tabs) and the same thing happens. It's like it shares data across the instances? I also tried the reverse - logging into the 2nd system first on a fresh instance, then login to the first, and the same thing happens with a similar "invalid login" error.

Maybe its something weird about the auth on our network, like SSO? ...

I have noticed similar though where I've had other, multiple private browser sessions open on my personal laptop and even though I've closed one of them, activity from the site I closed has continued to happen in the background because the other private windows remained open ...

I've been struggling today with accessing two systems on my work laptop. As I'm an administrator on both sites, I've been purposely using "private mode" browser sessions in Firefox (my default and fav) but I was surprised to see that the private mode appears to be "save" some of the session data from those systems - at least temporarily until I close all of those windows entirely? I log in to one of those corporate sites with a username + password, then attempt to login to the other one in a separate tab, but it immediately attempts to auto-login me in with the credentials from the first site (which doesn't work as both sites require a different username/password for security reasons). I tried several combinations: I used separate private browser windows (instead of tabs) and the same thing happens. It's like it shares data across the instances? I also tried the reverse - logging into the 2nd system first on a fresh instance, then login to the first, and the same thing happens with a similar "invalid login" error. Maybe its something weird about the auth on our network, like SSO? ... I have noticed similar though where I've had other, multiple private browser sessions open on my personal laptop and even though I've closed one of them, activity from the site I closed has continued to happen in the background because the other private windows remained open ...

Chosen solution

All PB mode windows (tabs) share the same in-memory storage like for cookies that only is purged if all PB mode windows are closed or if you exit/quit Firefox, so it isn't true that PB mode windows are independent. If you need multiple accounts then consider to use containers unless you do not want to keep history.

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you may check, wether different Firefox profiles will work 4 u : https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Multiple_profiles

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Chosen Solution

All PB mode windows (tabs) share the same in-memory storage like for cookies that only is purged if all PB mode windows are closed or if you exit/quit Firefox, so it isn't true that PB mode windows are independent. If you need multiple accounts then consider to use containers unless you do not want to keep history.

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Thanks for the quick responses. These are great resources and explanations. I think the containers option should do the trick. It's honestly what I thought was how the Private Windows/Tabs worked in general sense (a separate slice of the browser's storage space) ;)

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Quick update here: unfortunately the Multi-Account Containers didn't quite work for my situation, though it certainly sounded promising. I installed the add-on both at home and at work. Unfortunately, the feature doesn't work in "private browser" mode per the attached screen capture.

Definitely appreciated the insights though and totally worth a try. For now, I've switched to administering the one site in Chrome and the other in Firefox. Not ideal, but not the end of the world either :)

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Yes, you need to use regular mode and not PB mode if you use containers, otherwise you can open one account in regular mode and a second account in PB mode. If you insist in using PB mode then you need a separate profile for each account.