Firefox has this neat official extension Multi-Account Containers that is super useful to have, but just awkward enough that I wish they got more polish. You create "containers" and opened tabs are linked to those containers (or by default none). The idea being that you can have tabs opened with containers to the same site twice, with each one being its own account/session.
To open a container tab you have to hold down the new tab button which then shows a list of "containers". This opens a blank tab in that container and any URL you visit from there will remain in that container.
I used it the most when I was active on Twitter. By default opening the site would take me to my main account, but with container tabs I could open one, then visit the site and be logged in to an AD, my ZZT account (@worldsofzzt here), or any of my other bots that got killed off. It was a tremendous improvement over having to either log out of main and log in to an alt, or open up a private window and have to log in and not have anything saved to my history.
Infuriatingly, if you change what page you're posting from in one tab, Cohost will go ahead and change your page on every other active tab. Containers can be used to defeat this!
