Two Slack accounts on one Mac
Keep a client's or a second company's Slack in a second Slack on the same Mac: both open at once, each signed in to its own account, with its own notifications and Dock icon. Parallex is free and open source.
How
- Install Parallex (below). Your Slack isn't changed.
- Choose New Instance and pick Slack. Name it for what it's for, like “Slack Work”, and give it a color.
- Open it and sign in with the other account. Both run at once, each in its own windows, each with its own Dock icon.
What you get with Slack
- Its own copy of Slack, with its own Dock icon, name and color, its own notifications, and its own macOS permissions.
- Its own Library and keychain, so its sign-in, settings and caches are separate from your other Slack, and it has its own encryption key in the keychain.
- Guard keeps the copy out of the original's data, and the isolation check shows what the copy has opened of yours.
- Kept up to date by Parallex: Slack's own updater is turned off in the copy, and Parallex refreshes the copy when your Slack updates.
- Bringing the copy forward opens its window again if you'd closed it.
- Or, instead of a copy, a website instance of Slack (app.slack.com) in its own window, with its own sign-in and Dock badge.
Tested every night
Parallex's compatibility lab makes a fresh copy of Slack 4.52.155 every night on a clean Mac and opens it. On October 1, 2026, on macOS 26.6.2, the copy ran, and nothing reached the original's data. Its copies have run clean on all 2 nights since September 30. See every app's latest result.
Good to know
- A copy can't use iCloud sync, push notifications or Sign in with Apple, which belong to the original's signature. Apps that don't use them aren't affected.
Questions
Doesn't Slack already handle several workspaces?
It does, when they're all yours under one sign-in. A second Slack is for an account that has to stay apart: a client's Enterprise Grid, a second company, or one you want silent while you work in the other.
Does it change my Slack?
No. Your Slack isn't touched; the copy lives beside it, and removing the instance moves it and its data to the Trash.
Can both be open at once?
Yes, side by side, each in its own window with its own Dock icon and notifications.
Get Parallex
Free and open source, for macOS 14 and later. In Terminal:
curl -fsSL https://parallex.mandip.dev/install | shOr download it from GitHub, or with Homebrew: brew tap mandipadk/parallex https://github.com/mandipadk/parallex then brew install --cask parallex. Then choose New Instance, pick Slack, and give it a name.
Already have Parallex?
This opens New Instance with Slack picked; you name it and choose its color.
Make a second Slack