A multi account browser for a Mac, and how isolation really works

Two Google accounts, two Slack workspaces, a client Notion and a personal one. The search that follows is usually for a multi account browser, and the results present four very different things as if they were interchangeable: Google's own multi-login, browser profiles, Firefox containers, and applications that give each web service its own window. They separate at different depths, they break in different places, and picking the wrong one produces a setup that looks organized and still signs into the wrong account on a Tuesday afternoon.

Three problems get called the same thing

Before comparing tools, it is worth naming which problem is actually happening, because the same sentence covers three situations.

The first is that two accounts cannot be open at once. Signing into one signs the other out. This is a cookie and site storage problem, and no amount of tab arrangement touches it.

The second is that two accounts are open but the wrong one gets used. A link opens in the personal account, or the calendar shows a different identity than the inbox did. This is about which account a browser assumes when it cannot tell.

The third is that everything is separated correctly and switching still costs several seconds, thirty or forty times a day. That is not an isolation problem at all, and it is the one the first three tools on the list cannot solve.

Each of the four approaches below is good at one or two of these and silent about the others.

Google multi-login: free, instant, and Google-shaped

The lightest option is built into the Google account itself. Selecting the profile image at the top right of any Google page and choosing Add account signs in a second identity, and the same menu switches between them afterward. Google describes what that buys:

If you have more than one Google Account, you can sign in to multiple accounts at once. That way, you can switch between accounts without signing out and back in again. Source: support.google.com

Mechanically it works through a number in the URL. The account signed in first becomes index 0, the next becomes index 1, and the address of a mailbox carries that index. Bookmarking the indexed address opens the right mailbox directly, which is the fastest free trick available for two inboxes.

Settings stay mostly separate. Google states that account settings are usually not shared, so language and sign-in steps can differ per account. Nothing has to be installed, nothing costs money, and the setup takes under a minute.

The limit is the shape of it: the index is a Google mechanism, so it does nothing for Slack, Notion, or anything else. The moment a second service needs two accounts, this approach stops being the answer.

Where multi-login quietly gets it wrong

The second weakness surfaces later and is easy to misread as a bug. With several accounts signed in at the same time, Google cannot always determine which identity a given action belongs to. Opening a fresh browser window is the documented example: nothing in that window says which of the signed-in accounts was intended. Google states what happens next:

In cases like these, Google might apply settings from your default account, like its Web & App Activity and Ads Personalization settings. This can also affect country-specific services, like the Google Play store. Source: support.google.com

The default account is normally whichever account signed in first, so the quiet effect is that activity history and ad settings get recorded against an identity that was never chosen for the task at hand. The country case is the sharpest version of it. Google Play takes its country from the account's payment information, and with accounts registered in different countries the store can show content for the default account's country rather than the intended one. The fix Google offers is manual: switch to the correct account before browsing the store.

For someone using one work account and one personal account on the same machine, this means the boundary is real inside Gmail and fuzzy everywhere around it. It holds for reading mail. It gets vague for activity history, ads, store content, and any link opened from outside the browser.

Chrome profiles: a deeper cut with an admin cost

A browser profile separates more than cookies. Chrome documents profiles as keeping bookmarks, history, passwords, and other settings apart, created from the Profile control at the top right and given a name, photo, and color scheme. Signing a profile into a Google account names it automatically after that account.

This works for every site, not only Google ones, which is the decisive difference from multi-login. Work extensions do not run in personal tabs. Personal history does not appear in work autocomplete. Two windows, two colors, two identities, and no shared cookie jar between them.

The costs are administrative and social. Every extension has to be installed in each profile, and saved passwords split into separate stores. Chrome's own documentation adds a warning about shared machines: anyone holding the device can switch to any profile on it and see the sites visited there, so profiles are an organizing boundary rather than a security one.

One setting is worth turning on immediately. Under profile management there is an option to show the profile picker on startup, which makes the browser ask which identity to open before any window appears. Without it, the default profile opens first and the first action of the day happens in the wrong place often enough to matter.

Safari does the same thing, with one Mac-specific gap

Safari carries the same mechanism, and on a Mac it is the version that needs no install. Apple describes the purpose plainly:

You can keep your personal browsing separate from your work, school, and other browsing by creating a profile for each part of your life. Source: support.apple.com

Profiles live under Safari, Settings, Profiles. Each one gets a name, an icon, a color, a bookmarks folder of its own, and its own selection of extensions chosen at creation time. A Personal profile always exists alongside whatever gets added, and switching happens through File, New Window, and the named window for that profile, so the unit of separation is a window exactly as it is in Chrome.

What belongs to a profile is visible in what deleting one removes: Apple states that deleting a profile erases the tabs, history, and website data associated with it, while favorites folders survive. Sessions, in other words, are genuinely separate.

The gap is credentials. Apple notes that passwords stored in iCloud Keychain remain available in every profile that gets created. For someone who wants two identities but one password store, that removes the most annoying part of running Chrome profiles, where each profile keeps its own saved logins. For someone splitting profiles precisely so that a client's credentials are not reachable from personal browsing, the boundary stops short of where it was wanted, and the separation has to be enforced by a password manager instead.

Firefox containers: two accounts inside one window

Containers take a different shape. Rather than splitting the whole browser, they split cookies per tab, managed through an extension Mozilla publishes.

Under the hood, it separates website storage into tab-specific Containers. Cookies downloaded by one Container are not available to other Containers. Source: addons.mozilla.org

The practical difference from profiles is granularity. A profile splits windows. A container splits tabs, so two inboxes can sit next to each other in one window, each with a colored line along the top of its tab showing which identity is active. For work that involves comparing two accounts rather than alternating between them, that is a better fit than two separate windows.

The feature that makes containers hold up over time is per-site assignment: a domain can be set to always open in a chosen container, so an intranet link lands in the work container no matter where the click came from. The extension reports 403,827 users and a 4.6 rating across 8,059 reviews.

What stays shared is history, extensions, and saved passwords. And the whole approach requires using Firefox, which rules it out for anyone tied to Chrome by a work extension or a site that targets it.

The four approaches side by side

	Google multi-login	Chrome profiles	Firefox containers	Per-app windows
Cookie isolation	Google services only	Full	Full	Full
Works on non-Google sites	No	Yes	Yes	Yes
Extensions and history	Shared	Separate	Shared	Separate
Two accounts in one window	Yes	No	Yes	Depends
Setup required	None	Small	Extension	Install an app
Cost	Free	Free	Free	Usually paid
Reachable from the app switcher	No	No	No	Yes

The top four rows answer the isolation question, and on that question the free options are sufficient for most people. The last row is the one that behaves differently from the others, and it is also the one that decides how the day feels.

Why switching speed does not improve

Three of the four approaches draw the boundary inside the browser. To macOS, all of them are windows belonging to one application. The app switcher offers a browser, not a work inbox, so reaching a specific account always means getting to the browser first and then finding the right window or tab inside it.

Each round trip costs a few seconds. At thirty switches a day the arithmetic is unpleasant, but the real loss is attention rather than time: the few seconds spent hunting are long enough to lose the reason for switching in the first place.

The second shared weakness is links arriving from outside. Mail clients, chat apps, and calendar invitations hand a URL to the default browser with no indication of which profile or container it belongs to. Firefox absorbs part of this through site assignment, offering to reopen a registered domain in its container. Chrome profiles have no standard equivalent, so an external link opens wherever the default profile is and stalls at a sign-in screen.

Neither problem is a configuration mistake. Both follow from having one door into everything.

Choosing from the failure, not the feature list

Picking by feature comparison tends to produce a rebuild. Picking by the mistake that keeps happening does not.

Only Gmail and Calendar need two identities: multi-login is enough, and nothing needs to be installed. Several services each need two identities: profiles or containers, since multi-login does not reach them. Two inboxes get compared side by side all day: containers, because both fit in one window. Work and personal need a hard split including extensions and passwords: profiles, accepting the duplicate setup.

If the separation is already correct and switching is still the slow part, the remaining variable is the window model rather than the browser settings. Giving each service a permanent window and its own session turns switching into an application switch instead of a search through tabs, which is the approach behind SpaceDeck. The boundary between what stays a browser feature and what moves into the window is set out on the Features page, the list of services that can be registered is on Supported apps, and the differences against similar tools on price and platform are on the Wavebox comparison.

What to change first

Count the services that need two accounts. If the answer is one and it is Google, use multi-login today and stop there. If it is several, split profiles or add containers depending on whether the accounts get compared or alternated, and turn on the startup picker so the day does not begin in the wrong identity. Only after that is stable is it worth looking at the window model, and only if the switching itself is what still costs time.