Do Blackout Curtains Help Sleep? Who They Help and How to Fit Them

It is 5:10 a.m. in June. A bright strip of daylight is already on the ceiling, the birds have started, and you are wide awake with almost two hours left before the alarm. Or it is midnight and the streetlight outside turns your bedroom orange. So, do blackout curtains help sleep? For many people, yes, when light is the thing waking them up or keeping them up. They will not quiet a racing mind, and they come with one trade-off you should plan for: they also block the morning light that helps you feel awake. Below is how to tell if they will help you, and how to hang them so they actually work.

Imagine the sun comes up at 5 a.m. and you never find out. You sleep straight through to your alarm, and the first light you see is the light you let in yourself.

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Do blackout curtains help sleep? The honest answer

Your body uses light as its main clock signal. The Sleep Foundation’s guide to light and sleep says light at night can interfere with melatonin and sleep, and that the first step in setting up a bedroom for sleep is to make it as dark as possible. Blackout curtains are one of the simplest ways to do that for the whole room.

Light in the room may matter even when you do not wake up. In a small Northwestern University lab study published in PNAS, 20 healthy young adults slept either in dim light or with overhead room light on for one night. The room light group had a higher heart rate during sleep, spent less time in deep and REM sleep, and handled sugar less well the next morning. It was one night and a small group, so it is not the final word. But it is a good reason not to shrug off a bright bedroom.

So blackout curtains help most when light is genuinely reaching your eyes. If your room is already dark and you still lie awake, the problem is somewhere else, and new curtains will not fix it.

Who blackout curtains help the most

• Early wakers in spring and summer. If you wake at 5:15 from May to August but sleep until 6:45 in winter, that seasonal pattern is a strong hint that light is the trigger. Our guide to stop waking up so early covers the other causes too.
• People with a streetlight, car park or neighbor’s security light outside. City light is on all night, every night, and thin curtains barely touch it.
• Night shift workers and anyone sleeping in the daytime. Trying to sleep at 10 a.m. in a sunny room is hard work. Darkness is one of the biggest wins in sleeping when you work nights.
• Light sleepers. If small changes in the room pull you out of sleep, removing a whole category of disturbance can make the night calmer.

When blackout curtains will not help much

Be honest with yourself about what is keeping you awake. Curtains do little if:

• The light is inside the room. A phone in bed, a TV, a bright charger LED or a hallway light under the door all beat any curtain. Start with reducing blue light before bed and covering small LEDs with tape.
• You wake at 3 a.m. in a pitch-dark room. If it is already dark outside when you wake, light is not the trigger.
• Your mind is the thing that is on. Replaying the day or doing the math on how many hours are left is a nervous system that has not downshifted. Darkness helps, but you also need a way to settle your body, like the reset further down.

Blackout or room darkening: what to look for

Shop labels are loose, so check what you are actually buying.

• “Blackout” vs “room darkening”. Blackout curtains have a dense lining or coating meant to stop nearly all light. Room darkening curtains only dim it. For early sunrise or a streetlight, you want true blackout.
• Do the phone torch test. In a dark room, hold the fabric up and shine your phone light through it. If you can see the light clearly, so will your eyes at 5 a.m.
• Go wider and longer than the window. Most leaks come from the sides and the top, not through the fabric. A rod that reaches well past both sides of the frame, and curtains that reach the sill or floor, block far more.
• Close the edges. A wraparound rod brings the curtain back to the wall. Velcro strips or magnets can pin the sides. A pelmet or a rod mounted close to the ceiling stops the bright line above the curtain.
• Renting or on a budget? Removable blackout film or blackout roller blinds inside the frame, with curtains in front, work well together.

Blackout curtains vs a sleep mask

A mask is cheaper, travels with you and works in any room. Curtains darken the whole room and leave nothing on your face, which many people find more comfortable over a full night. If you share a bed with someone who reads late, a mask is often the quicker win. If you want the full comparison, read does a sleep mask help you fall asleep. Plenty of people use both: curtains for the room, a mask for the stubborn edges.

The one downside: you lose your morning light

The same Sleep Foundation guide lists getting morning sunlight as a healthy light habit for better sleep. A room that stays black until 9 a.m. can leave some people groggy and makes it easier to drift later and later. The fix is easy:

• Open the curtains as soon as your alarm goes, before you pick up your phone.
• Step outside or sit by a bright window for a few minutes in the first hour of your day.
• If mornings feel heavy, try the tips in sleep inertia every morning.

Dark at night, bright in the morning. That rhythm is what you are really buying.

Test it for a week before you spend money

Not sure light is your problem? Run a cheap test first. For seven nights, darken the window with what you have: a sleep mask, a spare duvet over the curtain rod, cardboard cut to the window frame, or a cheap pack of blackout film. Write down the time you first wake each morning. If you start sleeping past your usual early wake-up, blackout curtains are very likely worth it. If nothing changes, keep your money and look at the rest of your bedroom setup or at other light in the room.

If light already woke you tonight

Do not reach for the phone to check the time. Turn away from the window, pull the duvet up, and breathe in through your nose for a count of 4, hold for 7, then breathe out slowly through your mouth for 8. Do that four times. Many people find a long, slow exhale is what tells the body it is safe to let go again. Then let your attention rest on the weight of your body on the mattress, one spot at a time.

Quick answers

Do blackout curtains help with insomnia?

Only the part caused by light. If you struggle to fall asleep in a dark room, the cause is usually a wired body or a busy mind, not the window.

Are blackout curtains worth it for daytime naps?

Yes, if you nap or sleep after a night shift in a sunny room. Darkness makes it much easier to drop off in the middle of the day.

Can a room be too dark?

For sleeping, dark is the goal. The catch is the morning, so open the curtains when you get up and get some daylight early.

Light handled, but your body still will not switch off? The free 5-minute reset helps you downshift in bed tonight. Get the free sleep reset →