You're shopping for blinds and every listing says either "blackout" or "room darkening." They sound similar. They're not. Buying the wrong one means waking up to a bright room when you needed darkness, or overpaying for blackout when room darkening was enough.
The quick verdict
Blackout blocks 95-99% of light — near-total darkness. Choose this for nurseries, shift workers, and home theaters.
Room darkening blocks 70-90% of light — dimmed but not dark. Fine for most adult bedrooms, living rooms, and offices.
The numbers that actually matter
Manufacturers use these terms loosely, so focus on the light-blocking percentage rather than the marketing label. Here's what you'll actually experience:
When to choose blackout
Blackout is worth the extra cost when the stakes of light leakage are real:
- Nurseries. Babies are sensitive to light cues. Even a small glow can disrupt naps and early morning sleep. See our full nursery blackout guide →
- Night shift workers. You need to sleep during the day. Room darkening isn't enough when the sun is directly hitting your window.
- Home theaters / media rooms. Any ambient light washes out a projector screen.
- Street-facing bedrooms with bright lights. Streetlamps and car headlights at night need full blocking. Privacy blinds guide →
- West-facing rooms in summer. The afternoon sun is intense. Blackout shades also reduce heat gain significantly. Energy-saving guide →
When room darkening is enough
Don't overspend on blackout if you don't need total darkness:
- Adult bedrooms. Most adults sleep fine in a dimmed room. Room darkening cuts enough light for comfortable sleep while letting you see if you wake at night.
- Living rooms. You want to reduce glare and UV damage to furniture without making the room cave-dark during the day.
- Home offices. Room darkening reduces screen glare without eliminating natural light entirely. WFH blinds guide →
- Guest rooms. Room darkening is a safe, budget-friendly default.
The edge-gap problem: why "blackout" blinds still leak light
This is the most common complaint: "I bought blackout blinds and light still comes in." The fabric itself blocks 99% of light. The problem is the gaps around the edges — between the shade and the window frame.
How to fix it:
- Inside mount with tight fit. Measure precisely so the shade sits as close to the frame as possible. Mounting guide →
- Outside mount wider than the window. Overlap the frame by 2-3 inches on each side to cover the gaps.
- Light-blocking strips. Adhesive strips that attach to the frame and press against the shade. Cheap and effective.
- Side channels. Premium option — metal or plastic tracks that the shade slides into, eliminating side gaps entirely. Available from specialty retailers.
- Layer with curtains. A blackout shade plus blackout curtains covers every gap. This is the hotel/sleep-clinic approach.
Pro tip
If you're on a budget, a room-darkening shade with light-blocking strips often performs as well as a premium blackout shade without strips. The strips cost $5-10 and make a big difference.
How to read the label
Manufacturers aren't consistent with terminology. Here's how to decode listings:
- "Blackout" + percentage listed: Trust the number. 99% is true blackout. 95% is very good. Below 95% is really room darkening being marketed as blackout.
- "Room darkening" with no number: Assume 70-80%. It will dim the room but not darken it.
- "Light filtering": This is neither — it's a sheer/translucent shade that softens light but doesn't block it. Not what you want for sleep.
- "100% blackout": Refers to the fabric only. Light will still enter around the edges unless the shade has side channels.
Our recommendation
Best value blackout option
Cordless Cellular Blackout Shade
From $22/window — available at Amazon, Target, and Walmart
See our top picks →
Frequently asked questions
Is room darkening the same as blackout?
No. Room darkening blocks about 70-90% of light, leaving a visible glow. Blackout blocks 95-99%+ of light, creating near-total darkness. The difference is significant for nurseries, shift workers, and home theaters.
Do I need blackout or room darkening for a bedroom?
For most adult bedrooms, room darkening is sufficient — it dims the room enough for comfortable sleep. Choose blackout if you are a light-sensitive sleeper, work night shifts, live on a street with bright lights, or are setting up a nursery.
Why do some blackout blinds still let light through?
Even true blackout fabric blocks 99% of light through the material. The remaining light leaks in around the edges — the gaps between the shade and the window frame. To eliminate this, use side channels, light-blocking strips, or outside-mount the shade slightly wider than the window.