Two logins of one site, on a Mac

I make Overlay. Two logins of one site fight because a browser keeps one set of cookies per site, per profile. Sign in again and you overwrite the first. Every fix that works gives you a second cookie jar. The jars aren't the interesting part. The interesting part is whether those jars also have to show up over a fullscreen app, and how many you've got.

Can two logins of one site stay signed in?

Yes. Each login is a tab with its own cookies, so a work Slack and a client Slack don't kick each other out. The panel still sits over a fullscreen app. A browser profile doesn't do that part.

Open the site, sign in as the first person. Open it again, switch that tab to an isolated session, sign in as the second. The command is Isolated Session, on the tab's menu and as a button in the address bar. A third if you actually have one. They can sit side by side, same as any other two tabs, split if you want both timelines while the app underneath stays fullscreen.

What stays separate is the site's own data. Cookies, and the storage that site uses to remember you. What doesn't is an extension. Extensions run with one copy of their own login and settings, shared by the main session and the isolated tabs. Your password manager doesn't become two password managers. A grammar extension you've signed into doesn't become a second account. If you needed the extension itself to be a different person, you still want a browser profile.

Signing out, or clearing one site's data from the website-data screen, is per session. Clearing everything means everything, isolated tabs included. The confirmation is blunt. Read it.

When is a browser profile or Rambox the better tool?

A browser profile, if you switch a few times a day and you don't mind changing windows. Chrome, Edge, Arc, and Firefox all do this. Each profile is a full jar. Cookies, history, extensions. The cost is a window per person. Firefox containers do it in one window, with a color on the tab, if you'll use Firefox for those sites. Neither floats over a fullscreen app. Two Google accounts, a few times a day: stop here. Don't buy anything.

Rambox if the list is long. Several Slacks, several Gmails, WhatsApp, on Windows and Mac and Linux, left running. Workspaces group one client's accounts so you switch the set, not the tab. That grouping, and unlimited extra logins, are Pro. $7 a month or $70 a year on 25 October 2026. Free stops at two instances of each app, no workspaces, one computer. Overlay is a bad copy of that. Rambox is a bad copy of a panel over Xcode.

The mix is where Overlay earns it. The client site is fullscreen in the design tool or the editor. You also need to be the admin and the test user, in the panel, without logging the fullscreen session out. Profiles can do the jars. They can't do it without leaving the Space. Isolated tabs can.

Separate cookies aren't anonymity. The site can still tie you together with the IP, a fingerprint, or some other account you signed into on both sides. If the goal is privacy rather than not logging out, wrong page. You'll get a wall that isn't there.

The free options, written out: how to stay logged into one site on a Mac. Overlay is macOS 14 or later, $12 once after the trial. It won't merge those accounts into one inbox. Franz is the one aimed at a window you leave open for the messengers.