How to Keep Slack Active on Mac: What Works and What Doesn't

The short answer: most of the popular Mac advice does not work, and it fails for one reason. caffeinate, Amphetamine and Caffeine-style apps stop your Mac sleeping. Slack does not care whether your Mac is asleep — it cares whether there has been recent input. An awake Mac with an untouched keyboard still goes grey.

This is the single most common Mac mix-up on the subject, and it explains a lot of confused forum threads: the tool is working exactly as designed, and the Slack green dot disappears anyway.

Sleep Prevention Is Not Activity

macOS ships caffeinate, and its flags are all about power: -d keeps the display awake, -i prevents idle sleep, -m keeps the disk spinning, -s prevents system sleep on AC. None of them touch the keyboard or the mouse.

The flag that traps people is -u, documented as declaring that the user is active. It asserts activity to power management, which keeps the screen lit — and users consistently report Slack going away regardless. We go through this in detail in does Caffeine keep Slack active, including why the Windows tool of the same name behaves differently. See the caffeinate man page for the full reference.

Amphetamine and the Trigger Question

Amphetamine is the most capable Mac utility in this space, with triggers, timed sessions and app-based rules. It is genuinely good software and free on the App Store. But its core job is still keeping the Mac awake, so on its own it runs into the same wall.

It can be pushed further with mouse-movement style behaviour, which does generate input and does reset the timer. That works — while your Mac is on, unlocked and running Slack. Every local approach on macOS terminates at that same boundary.

What macOS Users Usually Actually Want

In practice the requirement is rarely “stop my Mac sleeping.” It is that availability should track working hours: green while you are working, whether or not you are typing, and genuinely away afterwards. Sleep prevention answers neither half, because it runs whenever it runs and stops when the machine stops.

NotAway maintains the workspace connection from a server on a schedule you set, so a closed MacBook does not end your presence, and up to seven workspaces can be held at once. It is $3.99/month with a 7-day free trial. For the general picture see how to keep Slack active and what Slack away status is measuring, alongside Slack’s own availability documentation.

If You Want the Free Route

If your Mac stays on and unlocked at one desk all day, use a jiggler-style tool or Amphetamine with mouse movement and pay nothing. That genuinely covers the common case, and there is no reason to buy a subscription for it. The case for a service is when your Mac is not the thing that stays on, or when you want presence bounded to real hours rather than to your laptop’s lid.