What is the difference between sleep, hibernate and shut down?
Where your open work physically is in each case — and that single fact explains the speed, the power draw and the risk of all three.
- Difficulty
- beginner
- Time
- 15 min
- Read
- 4 min
- Safety
- caution
Short answer
Sleep keeps everything in memory and keeps memory powered: it wakes in a second, and a flat battery loses your work. Hibernate writes memory out to a file on the drive and switches off completely: it takes longer to resume, uses no power, and survives a flat battery. Shut down closes everything and starts fresh next time. Use sleep for hours, hibernate for days or travel, and a genuine restart at least weekly.
The three options differ in one respect that determines everything else: whether the contents of memory are kept in memory, copied to the drive, or discarded.
Safety
Step by step
- Place sleep.Memory keeps its contents and keeps drawing a trickle of power. Nothing is written to the drive. Waking is near-instant with every window where you left it. The costs are a small continuous drain and total loss of unsaved work if power is lost.
- Place hibernate.The entire contents of memory are written to a file on the drive, then the machine powers off completely. Resuming reads that file back, which takes noticeably longer than waking from sleep but still restores everything. No power is used in between, and a flat battery costs nothing.
- Place shut down.Applications are asked to close, the system stops, and nothing is preserved. The next start is a fresh one. This is the only one of the three that clears accumulated state, which is why it is the fix for a surprising number of odd behaviours.
- Know that Windows shut down is not always a full shut down.By default, Windows uses a fast startup that saves part of the system state to disk on shutdown, making the next start quicker. It is effectively a partial hibernate, and it means shutting down does not always clear the state that a genuine restart does. This is why "restart" fixes things that "shut down and start again" does not.
- Use restart when troubleshooting.If you are trying to clear a problem, choose restart. On Windows it bypasses fast startup; on any machine it guarantees the system has actually gone through a full start.
- Match the choice to how long you are away.Under an hour or two: sleep, or just close the lid. Overnight or travelling: hibernate if the machine offers it, or sleep on a modern laptop with a good charge. Days, or before storage: shut down.
- Understand modern standby on newer laptops.Many recent laptops replace traditional sleep with a low-power state that stays partly awake to collect mail and updates, like a phone. It resumes instantly and is convenient, and on some machines it drains the battery noticeably more than the old sleep. If a laptop is losing charge overnight in a bag, this is usually why.
- Save before you close the lid, regardless.Sleep is reliable, and reliable is not certain. Anything unsaved lives only in memory in the sleep case, and that is where the losses happen.
If it doesn't work
Laptop battery is much lower after a night in a bag
Cause: Modern standby staying partly awake, or the machine waking in the bag — Fix: Hibernate or shut down before packing it. Some machines allow the standby behaviour to be changed in firmware settings; not all do.
Hibernate is not offered as an option
Cause: It is disabled by default on many machines, or turned off to reclaim the disk space its file uses — Fix: It can be enabled in the system's power settings. Note the hibernation file is as large as the installed memory, which is why some machines with small drives ship with it off.
Machine wakes slowly from sleep or with a black screen
Cause: Graphics driver or firmware handling of the resume — Fix: Update the graphics driver and the machine's firmware from the manufacturer. This is one of the more common driver-specific faults.
Machine feels sluggish after weeks without a restart
Cause: Accumulated state, memory not returned by long-running programs, updates pending a restart — Fix: Restart weekly. It is the least glamorous and most effective maintenance there is.
Questions people ask
Is it bad to leave a computer on all the time?
For a desktop that does useful work overnight, no — modern hardware is not damaged by being on, and thermal cycling from constant power switching is arguably harder on it. For a laptop it wastes battery cycles and heat. Either way, restart regularly.
Does shutting down every night save much electricity?
A sleeping laptop uses very little; a sleeping desktop with peripherals uses more. Over a year it is a small but real amount. The stronger argument for shutting down is that it forces a fresh start.
Which is best for the drive?
Hibernate writes a large file to the drive each time, which on a solid state drive consumes some write endurance — a negligible amount in practice on a modern drive. It is not a reason to avoid it.
Do Macs have hibernate?
Effectively yes. Apple laptops use a safe-sleep behaviour that writes memory to the drive as well as keeping it powered, so a battery that goes flat during sleep does not lose your session. It is not presented as a separate menu option.