Caffeine

Keeps your computer awake by preventing display and system sleep.

Quick Start

macOS

caffeinate -d

Windows (PowerShell)

# Keep display awake until Ctrl+C
while ($true) {
  $wsh = New-Object -ComObject WScript.Shell
  $wsh.SendKeys('{SCROLLLOCK}{SCROLLLOCK}')
  Start-Sleep -Seconds 60
}

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macOS

Uses the built-in caffeinate command (no installation needed).

Options

| Command | Effect | |---------|--------| | caffeinate | Prevent sleep until terminated | | caffeinate -d | Prevent display from sleeping | | caffeinate -i | Prevent idle sleep | | caffeinate -s | Prevent system sleep (AC power only) | | caffeinate -t 3600 | Prevent sleep for 1 hour (seconds) | | caffeinate -d -t 1800 | Keep display on for 30 minutes |

Examples

Keep display on for 2 hours:

caffeinate -d -t 7200

Keep awake while a command runs:

caffeinate -i -- long-running-command

Run in background:

caffeinate -d &
# To stop later:
pkill caffeinate

Check if running:

pgrep -l caffeinate

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Windows

Option 1: PowerShell (no install)

Prevent sleep by simulating activity (Ctrl+C to stop):

while ($true) {
  $wsh = New-Object -ComObject WScript.Shell
  $wsh.SendKeys('{SCROLLLOCK}{SCROLLLOCK}')
  Start-Sleep -Seconds 60
}

Option 2: powercfg (change power settings)

Disable sleep temporarily:

# Disable sleep on AC power
powercfg /change standby-timeout-ac 0
powercfg /change monitor-timeout-ac 0

# Re-enable later (e.g., 30 minutes)
powercfg /change standby-timeout-ac 30
powercfg /change monitor-timeout-ac 15

Option 3: Presentation mode

# Enable presentation mode (disables sleep + notifications)
presentationsettings /start

# Disable when done
presentationsettings /stop

Option 4: One-liner with .NET

# Prevent sleep for duration of script
Add-Type -AssemblyName System.Windows.Forms
while ($true) {
  [System.Windows.Forms.Cursor]::Position = [System.Windows.Forms.Cursor]::Position
  Start-Sleep -Seconds 60
}

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Notes

• macOS: caffeinate is built-in; process must stay running
• Windows: PowerShell methods simulate activity; powercfg changes system settings
• Press Ctrl+C to stop any running script