Experiment guides → Bedroom & environment → No phone in bedroom

Does a no-phone-in-the-bedroom rule improve sleep?

A 14-day self-experiment guide · Last updated September 5, 2026

Quick answer: the observational evidence says yes, and the rule is the cleanest way to test it. In a survey of 844 adults, using a phone after lights-out was associated with later bedtimes, longer time to fall asleep, shorter sleep, worse sleep quality and more daytime fatigue. In 653 adults whose screen time was measured by an app rather than recalled, more use near bedtime went with poorer sleep quality and slower sleep onset. The mechanism has two parts — light that delays the clock, and content that keeps the mind running — and putting the phone in another room removes both at once. It costs an alarm clock and a charger in the hallway. Two weeks tells you what it was doing to your nights.

"My phone will charge outside the bedroom for 14 nights."

What the research says

Phone in bed, worse sleep — across 844 adults. Exelmans and Van den Bulck surveyed 844 Flemish adults aged 18–94. Mobile phone use after lights-out was common, and it was associated with later bedtimes and rise times, longer sleep latency, shorter sleep, poorer sleep quality, more insomnia symptoms and more fatigue. The associations held across ages, not just in the young (Exelmans & Van den Bulck, 2016).

Measured, not remembered: screen time near bedtime tracks poor sleep. Christensen and colleagues installed an app on 653 adults' phones to log actual screen-on time over 30 days. More total screen time was associated with poorer sleep quality and less sleep, and screen time within an hour of bedtime was specifically associated with poorer sleep quality and longer time to fall asleep — data from the device, not from memory (Christensen et al., 2016).

Why: the light alone shifts the clock. In Chang's controlled crossover, reading on a light-emitting device for four hours before bed for five nights — versus a printed book — suppressed evening melatonin by about 55%, delayed the circadian clock by about 1.5 hours, lengthened sleep onset by about 10 minutes, reduced REM sleep and left people sleepier the next morning. The phone's content adds arousal on top of that (Chang et al., 2015).

What this evidence doesn't say

The two population studies are correlational: poor sleepers may reach for the phone because they can't sleep. The light study used four hours of a bright tablet — more than most bedtime scrolling — and no trial has randomised adults to a no-phone rule. The rule removes several things at once (light, content, the temptation to check the time), which makes it effective but means a positive result doesn't tell you which part mattered.

Run it as an experiment

  1. Baseline five nights with the phone where it usually lives. Sleep quality, restedness, time-to-sleep — and, honestly, the last time you looked at the screen and the first time you looked in the morning.
  2. Buy an alarm clock and move the charger. The hallway, the kitchen, anywhere that needs you to get out of bed. "Face-down on the nightstand" doesn't count; the point is that checking requires a decision.
  3. Make the pact. "My phone will charge outside the bedroom for 14 nights." Decide now what you'll do instead in the ten minutes before sleep — a book, a podcast on a speaker, nothing.
  4. Morning check-ins, plus the urge note. The three ratings, and whether you wanted the phone at lights-out or on waking in the night. The urge usually fades by night four; its persistence is information about habit, not sleep.
  5. Compare time-to-sleep and the morning. Those are the outcomes the data predict. Better? Keep the rule. Same? Your phone wasn't the problem — try a caffeine cutoff or a fixed wake time next, and enjoy the phone back.
Want this structured for you? Run it in N of 1 — baseline nights, morning check-ins and an honest result, ready to go. Your first experiment is free.

What to expect

The most common report is falling asleep faster and, less expectedly, waking more easily — partly because there's no screen to check at 3 AM, so the brief waking stays brief. Nights one to three often feel restless as the habit protests. If you use the phone for a sleep app or white noise, the experiment still works: a speaker across the room or a dedicated device keeps the function and removes the screen.

Who should skip this

If you're on call, or need to be reachable for a child or a dependent, keep the phone in the room on a do-not-disturb schedule with exceptions — and test the screen-free wind-down experiment instead, which addresses the same problem without moving the device.

Frequently asked questions

Why should you not sleep with your phone in the bedroom?

Three reasons the evidence supports: screen light delays your clock and suppresses melatonin, content keeps your mind active, and the phone turns every brief night waking into a scrolling session. Moving it removes all three.

How far away should your phone be when you sleep?

Far enough that checking it means getting out of bed — the room next door. The distance isn't about radiation; it's about friction. A phone within arm's reach gets used.

Does phone light at night really affect sleep?

In a controlled study, four hours of a bright tablet before bed cut melatonin by about half and delayed the body clock by about 1.5 hours. Ordinary scrolling is shorter and dimmer, so the effect is smaller — but it's on top of the arousal from what you're reading, which the light studies didn't even measure.

Related experiments

Does screen time before bed affect sleep quality? · Is blue light before bed a myth? · Does sleeping in total darkness improve sleep?

Sources

  1. Exelmans L, Van den Bulck J. Bedtime mobile phone use and sleep in adults. Soc Sci Med. 2016;148:93–101. PubMed 26688552
  2. Christensen MA, Bettencourt L, Kaye L, et al. Direct measurements of smartphone screen-time: relationships with demographics and sleep. PLoS One. 2016;11(11):e0165331. PubMed 27829040
  3. Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci U S A. 2015;112(4):1232–1237. PubMed 25535358

Track this experiment in N of 1

A few baseline nights, then the change — and your own mornings deliver the result. No streaks, no guilt. Your first experiment is free.

Downloadon the App Store

This page is general information about published research, not medical advice. If you have a sleep disorder, are pregnant, or take medication, talk to your doctor before changing your routine.