Screens & Sleep
How Long Before Bed Should You Stop Using Screens
By Nora Vale · November 5, 2025 · 7 min read
You’ve heard “no screens before bed” so many times it has stopped meaning anything, and the honest answer needs a number. The one the sleep research world actually uses is a reasonable target of minimal screen use across the two or three hours before bed. That number surprises people twice: it’s longer than they hoped, and it’s also the wrong thing to obsess over, because what you stop matters more than exactly when you stop. This piece gives you both, the target and the version that fits a real week, and the whole picture lives in my screens and sleep guide.
Key takeaways
- The research target is minimal screen use in the two or three hours before bed.
- The practical line is about feeds, not photons: no infinite scroll in the final hour.
- Night mode helps a little and changes the cutoff almost none.
- Passive screens late are the gentle end; interactive feeds are the expensive end.
- Stair-steps are legitimate: dock the phone first, then shrink the window.
Where the two to three hour number comes from
The timing target comes from the light story, and it’s worth knowing the dose behind it. In 2015, researchers at Brigham and Women’s Hospital in Boston ran the experiment this whole conversation keeps quoting. People read for hours before bed, some on light-emitting tablets and some on printed books. “The tablet readers’ melatonin arrived about ninety minutes late.” They took roughly ten minutes longer to fall asleep and their body clocks shifted later as well.
Notice the dose, though, because the dose is the story. That result came from hours of bright, close-range light held about a foot from the face, night after night, not from a last check of tomorrow’s weather. “A phone is a small sun you hold about a foot from your face,” but the sun in question is small, and an hour of evening daylight delivers more light to your body clock than an entire night of scrolling. The two-to-three-hour number is honest science applied to a worst case most evenings don’t reach.
The cutoff that actually matters: feeds, not photons
Here’s the line I’d actually draw, and it’s simpler than the lux math. “nothing with an infinite scroll in the final hour, even dimmed, even in a warm sepia glow.” If the content wakes your mind up, it barely matters that the screen is dim, and if the feed eats forty-five minutes, no night-mode setting hands them back.
The feed deserves the hard line for two reasons. First, it’s a slot machine that asks your brain a question with every swipe, and each answer is a small dose of alertness at the exact hour alertness is least useful. Second, it steals time invisibly. One man got into bed at 10:50 to check the weather for a morning run and looked up at 11:37 doing the math on six hours of sleep, with no memory of most of the 45 minutes between. The feed steals time rather than quality, and it does it so smoothly that the theft doesn’t feel like anything while it’s happening.
What screens can stay, and until when
A cutoff that bans everything fails by Wednesday, so rank your screens instead. Passive is the gentle end of the spectrum. A show you chose, watched in the living room with the lights low, is a different weight class from forty-five minutes of the replies. The interactive stuff, the replying, posting, and refreshing, is what holds your mind in third gear, so that’s what the earliest cutoff applies to.
Two tests sort the survivors: can it end on its own, and does it come with a feed. An e-reader with the front light low passes. A podcast or audiobook with a sleep timer passes, and a familiar-voiced show at low volume has carried me to sleep more nights than I can count. A phone displaying a book fails the second question, because the entire arcade is one swipe away. Paper is the gold standard, and the library supplies it for free.
Building a cutoff you’ll actually keep
The rule has to be decided before the hour it governs. Decisions made at 11 p.m., phone already warm in your hand, resolve about as reliably as decisions to have one more drink. Decide at nine where the phone sleeps and when the feed closes, and the eleven o’clock version of you never gets a vote. The mechanics of that decision, including the ten-dollar alarm clock that removes the last excuse, are in should I charge my phone outside the bedroom.
A closed cutoff leaves a hole, and a hole with nothing planned for it is how the phone gets rehired. Fill the last hour on purpose: one low-effort thing for your body, one for your mind, one for the room, same order each night. If the whole move feels too big, the stair-step is legitimate and I’d rather see you take it than admire the complete version from the couch. Dock the phone in the bedroom first, then make the final 30 minutes feed-free, then stretch the window toward the two-hour mark over a few weeks.
And when a bad-news week blows the cutoff, lose the hour and start over without treating it like a moral event. “The feed will still exist at 7 a.m. Your sleep window won’t.” The book behind this chapter, with the full evening protocol, is Sleep, Finally. Set your own cutoff now, while it’s cheap to decide.
Frequently asked questions
How long before bed should you stop using screens?
The research target is minimal screen use across the two or three hours before bed. The line I’d actually draw is about feeds rather than photons: nothing with an infinite scroll in the final hour, even dimmed. That single rule captures most of the damage the longer number is trying to prevent.
Do I have to quit screens entirely in the evening?
No. A show you chose, watched in the living room with the lights low, is passive content and the gentle end of the screen spectrum. The interactive stuff, replying, posting, and refreshing, is what holds your mind in third gear, so the hard cutoff belongs to feeds and inboxes, not to every glowing rectangle.
Does night mode change how early I should stop?
Not really. Night mode treats the light half of the problem, which is the smaller half. If the content wakes your mind up, it barely matters that the screen is dim, so the cutoff still applies. Turn night mode on anyway, since it costs nothing, but don’t let it stand in for the feed rule.
What if I can’t manage two or three hours without screens?
Take the stair-step: screens off the bed first, then the final 30 to 60 minutes feed-free, then stretch the window over a few weeks. A rule you keep beats a rule you admire, and partial versions that hold are worth more than perfect ones that don’t survive Tuesday.
This guide is educational, not medical advice. If you find the cutoff impossible to keep, or sleeplessness persists for weeks, that’s a conversation for a doctor rather than a settings change.
