Mozilla has released its Firefox Multi-Account Containers add-on which lets you containerize all of your online lives. Any cookies that are downloaded in one container are not available in other containers so you can keep, for example, your personal browsing completely separate from work-related browsing.
While you can use the add-on to keep your work and private life separate, you can also use it in order to login to the same site with a different account, Mozilla said:
“Each Containers stores cookies separately, so you can log into the same site with different accounts and online trackers can’t easily connect the browsing.”
The add-on is a “graduate” of the Containers Firefox Test Pilot program which is still available to join, strangely. One important caveat with the plug-in is that you’ll only be able to sync your Firefox data with one Firefox Account; it’s not clear whether Mozilla plans to change this in the future, but for the time being that’s the way things stand.
Once installed, you’ll be able to keep track of all your different personas with color-coded tabs. In the URL bar, you’ll also see text identifying which session the current tab belongs to so that you don’t inadvertently go to any websites with which you don’t want your account associated.