There is an entire genre of software named after coffee whose one job is stopping your computer from going to sleep. Caffeine. Caffeinated. Amphetamine, presumably for when coffee stops working. They all press pause on the sleep timer without making you dig through power settings, and they have been quietly excellent for years.
But they are not all the same, and there is one thing none of them do that catches almost everyone out. So here's the honest tour, Windows first.
Caffeine for Windows: the original hack
Zhorn Software's Caffeine has been around since roughly forever. It sits in the system tray and simulates an F15 keypress every 59 seconds. Windows sees a key event, decides you must be busy, and holds off sleep. Double click the tray icon to toggle it. That is the entire app, and the entire app is the appeal: tiny, portable, free.
The keypress approach is also its quirk. F15 doesn't exist on most keyboards, so it's usually harmless, but you are still injecting phantom input into whatever has focus, and some locked-down corporate machines take a dim view of input simulation. It feels like a hack because it is one. A well-behaved, twenty-year-old hack.
PowerToys Awake: Microsoft's own answer
The tidy option. Awake ships inside PowerToys, Microsoft's free open-source utility bundle, and it asks Windows to stay awake through the proper API instead of faking anything. No keypresses, no edits to your power plan, nothing to undo afterwards. You can keep the PC awake indefinitely, for a set interval, or until a time you pick, and there's a separate tick box for keeping the display on.
If you're on Windows and just want the machine to stay up, this is the sensible default. We've written a full walkthrough in PowerToys Awake explained if you want the details.
Amphetamine: the Mac power tool
Over on the Mac, Amphetamine is the power user's pick, and somehow it's free on the Mac App Store. Sessions with durations. Triggers that start a session automatically when a particular app is running, a display is plugged in, or you're on a certain wifi network. AppleScript support if you want to get properly weird with it.
It is genuinely excellent software. It's also complete overkill if all you want is "don't sleep for the next hour", which describes most people, most days.
Caffeinated and KeepingYouAwake: the simple cups
If Amphetamine is too much, these two are the gentler Mac options. Both live in the menu bar as a coffee cup. Click the cup, the Mac stays awake. Click again, normal service resumes. KeepingYouAwake is free and open source, and under the hood it's a friendly wrapper around the caffeinate command below. Caffeinated is a similar polished take with timers, for a small one-off cost. Neither will ever surprise you, which is exactly the point of them.
caffeinate: the one you already own
Every Mac ships with a keep-awake tool and nobody mentions it. Open Terminal, type caffeinate -d, press return. The display stays awake until you hit Ctrl+C. Want a timer? caffeinate -d -t 3600 buys you an hour. Free, already installed, zero menu bar clutter.
The catch is remembering the flags and keeping a Terminal window knocking about, which is more or less why the menu bar apps exist.
Side by side
| Tool | Platform | Keeps machine awake | Creates input | Price |
|---|---|---|---|---|
| Caffeine for Windows | Windows | Yes | A phantom F15 tap | Free |
| PowerToys Awake | Windows | Yes | No | Free |
| Amphetamine | Mac | Yes | No | Free |
| Caffeinated | Mac | Yes | No | Small one-off cost |
| KeepingYouAwake | Mac | Yes | No | Free |
| caffeinate command | Mac | Yes | No | Free, built in |
| Green Dotter | Mac and Windows | Yes | Yes, clicks and wiggle | Free |
The gap none of them fill
Every tool above solves the same problem: the machine going to sleep. None of them solve the other problem people are usually googling at the same time, which is Teams or Slack marking them Away.
Presence apps don't care whether your computer is awake. They watch for input. Keyboard, mouse, actual human fidgeting. Keep-awake tools deliberately create none of it, so the laptop hums along fully awake while your dot goes yellow. Caffeine's F15 tap is the near exception, and even that is a single phantom function key that presence detection often shrugs off.
Screen lock is the other wrinkle, and it differs per tool. Keeping the display on usually holds off the screensaver lock, but a managed machine with a policy-enforced idle lock can still lock on schedule, awake or not, and on most setups the lock drags your presence down with it. If your goal is simply staying awake without touching system settings, that side is covered in keeping your computer awake without changing settings. If your goal includes the green dot, you need something that makes input, not just something that blocks sleep.
Where Green Dotter fits
Green Dotter does both halves. There's a keep-awake toggle for the machine, and when presence matters it creates actual activity: occasional clicks in a screen area you choose, or a gentle mouse wiggle, on a randomised schedule so it reads as human rather than metronomic. Real input is the thing Teams and Slack are actually checking for, and it's precisely the bit the coffee apps skip.
Free, on Mac and Windows, and it runs locally with no account. If you arrived here from the PowerToys side of the internet, the PowerToys Awake alternative page covers that comparison properly, and the keep computer awake page covers the sleep half on its own.
FAQ
Is there a Caffeine app for Windows?
Yes. Caffeine for Windows by Zhorn Software is a free tray tool that simulates a keypress every 59 seconds so Windows never thinks you have gone idle. Microsoft's own PowerToys Awake does the same job more cleanly, through the proper API rather than fake input, and it is also free.
What is the Mac equivalent of Caffeine?
Amphetamine is the closest match, free on the Mac App Store, with sessions and triggers for people who want control. KeepingYouAwake and Caffeinated are simpler menu bar coffee-cup toggles. And macOS already ships with the caffeinate Terminal command, which needs no install at all.
Do keep-awake apps keep Teams or Slack active?
Generally no. They stop the machine sleeping, but Teams and Slack watch for keyboard and mouse input, and keep-awake tools deliberately create none. Your laptop stays on while your status drifts to Away. Presence needs actual activity, which is a different job.
Is there a built-in way to keep a Mac awake?
Yes. Open Terminal and run caffeinate -d and the display stays awake until you press Ctrl+C. Add a timer with -t and a number of seconds, for example caffeinate -d -t 3600 for an hour. Free, already installed, no menu bar clutter.
Is PowerToys Awake free?
Yes. Awake is part of Microsoft PowerToys, a free open-source bundle of Windows utilities. It keeps your PC awake indefinitely or for a set time, with a separate option to keep the display on, and it does not touch your power plan while doing it.
A note on workplace policies: how you handle presence depends on your role, your tools, and your employer's policies. Before relying on any presence or automation tool, make sure you understand what is allowed on your work device.
Related: download the Mac auto clicker or the Windows auto clicker.