Keep awake: stop your Mac sleeping for a set time

Keep awake holds off sleep for a stretch of time — through a long download, a presentation or an export — and then ends by itself. It needs no administrator rights and doesn't change any lasting setting.

Start it

1. Open Browse all and pick the Power chip.
2. On the Keep awake card — “Stop your Mac sleeping for a set time — no admin, no Terminal.” — click 30 min, 1 hour or 2 hours.
3. The card now reads “Awake until” and the end time, for example “Awake until 4:30 PM”.

Any other length

1. Click Custom. A small box appears, labelled minutes.
2. Type a number — 90, say — and click Start or press Return. Start stays grey until you type a whole number above zero.

Stop it early

While Keep awake is running, the card shows only Stop. Click it to end the timer early; to pick a different length, stop it first and choose again.

What it does

Keep awake runs Apple's own caffeinate tool with a timer. For the whole period the display stays on and the Mac won't idle into sleep. When the time is up, caffeinate exits and your normal sleep settings take over — there's nothing to reset. The card goes back to its buttons within about 20 seconds.

For a MacBook that has to keep running with the lid shut, use Never sleep instead. Keep awake isn't listed in On now; its card shows when it ends.