How to use this site

Work through the site in order, one habit at a time. Level 1 first: it’s free, and for most people it makes the biggest difference.

The levels

1. Basics. Wake time, light, caffeine, alcohol, naps, screens, late meals.
2. Bedroom. Temperature, darkness, noise, mattress, pillows and bedding.
3. Routine and timing. Wind-down, exercise and meal timing, baths, chronotype, weekends, travel.
4. Advanced. Supplements, breathing and relaxation techniques, sleep restriction, night waking.

Wearables is separate: read it whenever you like if you track your sleep.

One change at a time

Change one thing, keep it for one to two weeks, then add the next. If you change five things at once, you won’t know which one helped, and you’ll probably drop them all.

The badges

Every topic page starts with the same row of badges:

• Evidence: how strong the research is (see below).
• Effort: how much it asks of you. Low, medium or high.
• Cost: free, low, medium or high.
• Works: roughly how soon you’d notice a difference. Where studies don’t say, this is our estimate, and the page says so.

Under the badges, Changes lists the sleep metrics the habit can move: time to fall asleep, deep sleep, REM, HRV, resting heart rate, efficiency, timing and total sleep. Tap one to see every page that affects it.

Evidence ratings

• StrongClinical guidelines, meta-analyses or several good trials agree.
• SomeA few trials or consistent observational studies. Likely true, size of effect uncertain.
• WeakSmall, short or mixed studies. Might help; might not.
• UnknownNot studied well enough to say, or we could not verify a source.

The rating is for the main recommendation on the page. When the evidence is weak or mixed, the page says so in its first paragraph, not at the end.

We prefer sources in this order: clinical guidelines, systematic reviews and meta-analyses, randomized trials, large observational studies, then expert consensus. Each source in a page’s list is labelled with its type. Wearable details come from the manufacturer’s own public documentation.

How each page is laid out

1. Short answer. The recommendation in two or three sentences.
2. Why it matters.
3. How to do it. Numbered steps.
4. Common mistakes.
5. Effect on your sleep score. Which metrics, how much, and how sure we are.
6. Evidence. What studies show, and their limits.
7. Try this week. One specific thing to do.
8. Sources. The numbers in square brackets, like [1], link straight to them.

What this site is not

It’s for healthy adults who want to sleep better. It doesn’t diagnose or treat sleep disorders. If you snore loudly and are sleepy during the day, stop breathing or gasp in your sleep, or have had insomnia for more than three months, read when to see a doctor first.

Where to start

Go to Level 1: Basics and start with a consistent wake time. It’s free, and it makes the other habits easier.