Hi Rick, the way Firefox Sync works is to share and merge your data between different Firefox installations. That data then is saved locally on each Firefox installation you Sync so it's mostly available offline and when you disconnect from your account.

Do you need to delete locally stored data from a computer?

Note that for saved logins, you can add a layer of protection using a Primary password. This secures the locally stored data and is separate from your Firefox Account login. More info: Use a Primary Password to protect stored logins and passwords.

How many devices did you sync with?

laptop, (home) mobile device and my office, which I am trying to log out when I leave

Hi Rick, the way Firefox Sync works is to share and merge your data between different Firefox installations. That data then is saved locally on each Firefox installation you Sync so it's mostly available offline and when you disconnect from your account. Do you need to delete locally stored data from a computer? Note that for saved logins, you can add a layer of protection using a Primary password. This secures the locally stored data and is separate from your Firefox Account login. More info: Use a Primary Password to protect stored logins and passwords.

This i understand, however can you log out of one device (completely) and your add-ons and logins will become inaccessible? When when you log back into fox, it can catch up as needed?

Not sure what the reason for logging in and out.

This i understand, however can you log out of one device (completely) and your add-ons and logins will become inaccessible? When when you log back into fox, it can catch up as needed?

No, logging out -- disconnecting from Sync -- doesn't "lock" that installation of Firefox or provide any way to block access to data stored by that Firefox. (Possibly Firefox might ask if you want to flush ALL of your data when signing out, but usually you don't want to do that unless you are on someone else's computer because you'd probably have unrecoverable data loss.)

Rick (Proton) said

This i understand, however can you log out of one device (completely) and your add-ons and logins will become inaccessible? When when you log back into fox, it can catch up as needed?

No, logging out -- disconnecting from Sync -- doesn't "lock" that installation of Firefox or provide any way to block access to data stored by that Firefox. (Possibly Firefox might ask if you want to flush ALL of your data when signing out, but usually you don't want to do that unless you are on someone else's computer because you'd probably have unrecoverable data loss.)

Thanks for the quick response, okay so good so far. So what's the purpose of logging in and out if it doesn't protect your data. Traditionally with all logging in and logging out practices, it's to protect your data. Be it an online game to a bank account. You login at any device or any media to access your bank account or your gaming account. When you log out all information becomes inaccessible. The Firefox this is not true, so just curious what the purpose of logging in and logging out does. Thank you again for your prompt responses they are very informative

Normally, you wouldn't sign out/disconnect Firefox from Sync or other Mozilla services if you use them. I suppose if you were worried that an attacker might delete or pollute your data and that would propagate to your other Firefox installations, that would be a good reason to sign out/disconnect when you are not actively using Sync or other Mozilla services.

Normally, you wouldn't sign out/disconnect Firefox from Sync or other Mozilla services if you use them. I suppose if you were worried that an attacker might delete or pollute your data and that would propagate to your other Firefox installations, that would be a good reason to sign out/disconnect when you are not actively using Sync or other Mozilla services.

Ok, thank you. The real reason for this question is because I use Fox on my computer at work (normally I am the only one that has access to that office, but I do log out of the computer, but on the happen chance I do not, I would hate for someone to have access to the logins - I log out of the windows account, jut a smidge paranoid that someone could get into windows and log into my account. Not likely - but these days - who knows.

Thank you very much for your conversation and clarity. I will tack the master pw back on. extra step never hurts. :-)

It's an interesting scenario. If someone switches on the computer and logs in as an admin -- unlikely they could log in as you -- they would have access to the local data files in all the user profiles. Using the Primary password will strengthen the encryption on the saved logins making the data hard to use for someone who grabs the files.

Well fortunately for me, I am the only nerd in the company LoL (I do maintenance work for several properties - just thought it odd, when I singed out, the browser was still fully exposed)

Sync is meant to be used to sync data among devices that are connected to this Firefox Sync Account. This means that data from every device is uploaded to the Sync server and is merged (downloaded) to the other devices (i.e. all devices eventually get the same data). If you logout from Sync then this merely means that you no longer upload new data to the Sync server and that you also do not get new data from other devices. Logging out doesn't affect data locally stored in the Firefox profile folder on a device. If you only connect one device to Sync then there is not much merit as Sync isn't meant to be used as a backup. You should always backup your personal data locally.

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Sync is meant to be used to sync data among devices that are connected to this Firefox Sync Account. This means that data from every device is uploaded to the Sync server and is merged (downloaded) to the other devices (i.e. all devices eventually get the same data). If you logout from Sync then this merely means that you no longer upload new data to the Sync server and that you also do not get new data from other devices. Logging out doesn't affect data locally stored in the Firefox profile folder on a device. If you only connect one device to Sync then there is not much merit as Sync isn't meant to be used as a backup. You should always backup your personal data locally.

• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Totally understand. I am old school, you log out - your data is not available locally or otherwise. You log back in, your data then syncs back up. Not sure what the reasoning behind logging out (and in) if your data is still available. I understand it is still stored locally, but one would think that the logging in/out makes available or blocks that access. IMHO.

thanks for the reply!!

From what you write I get the impression that you think that your personal data is stored on the Sync server (i.e. in the cloud), so only if you login to Sync then you have access and if you logout then you no longer have access. This isn't the case, your personal data is stored locally in the Firefox profile folder and stays there at all time and running Firefox has nothing to do with Sync.

If you want to inspect your personal data then you can use the button on the "Help -> More Troubleshooting Information" (about:support) page to go to the current Firefox profile folder.

• Help -> More Troubleshooting Information -> Profile Folder/Directory:
  Windows: Open Folder; Linux: Open Directory; Mac: Show in Finder
• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

From what you write I get the impression that you think that your personal data is stored on the Sync server (i.e. in the cloud), so only if you login to Sync then you have access and if you logout then you no longer have access. This isn't the case, your personal data is stored locally in the Firefox profile folder and stays there at all time and running Firefox has nothing to do with Sync. [snip]

Hi, I understand this. Where it is stored is not the issue, cloud/local, what is the issue it shows I am logged out and that data should (technically) not be available until I sign back in. My original post now has branched off to a secondary question related to the first: What does logging out do? I know how syncing works. What I was asking, (or should have) is why can't logging out "disconnect" from the local sensitive data as well. and NOT just they syncing part of it. Hope that made sense. Logins (and maybe add-ons) are vulnerable no matter where it is stored. If you are logged out of your browser, syncing stops - that works, why not add something to block the other data - addons/logins etc...

Example: Lastpass is a addon, addons WORK when you are logged out of FF. Scary.

thanks.

When you logout then this merely means that your personal data on the Sync server no long is updated. How many devices are connected to this Sync account ?

Locally there is no difference unless you have other devices connected to this Sync account as you no longer see data from the other devices.

My original post now has branched off to a secondary question related to the first: What does logging out do? I know how syncing works. What I was asking, (or should have) is why can't logging out "disconnect" from the local sensitive data as well. and NOT just they syncing part of it. Hope that made sense. Logins (and maybe add-ons) are vulnerable no matter where it is stored. If you are logged out of your browser, syncing stops - that works, why not add something to block the other data - addons/logins etc...

A browser could work that way. Either it could store your data only in the cloud, inaccessible until you sign in, or it could encrypt your local data folder and operate in a "guest" mode until you sign in to your individual profile with a key that allows it to decrypt your data folder. But I don't know whether any browser actually does work that way. Firefox definitely does not.