A free, 3-week course · text, quizzes and tools, no video

Sleep, Decoded: Understand and improve your sleep in 3 weeks

15 to 20 minutes a day. Measure your own sleep, test one change, leave with a plan that fits your life.

Start Module 1

How it works

Week 1: see your sleep

Keep a 7-day diary exactly as you sleep now, and learn how much sleep you need and what a short night costs.

Week 2: change one thing

Pick one change from the evidence and test it on yourself for 7 days, still keeping the diary.

Week 3: solve and keep

Compare your two weeks, learn when to see a doctor, and write a sleep plan you can keep.

Get each new module by email

Module 2 opens on Tuesday 6 October. One short email when each module opens, with the link. No spam; unsubscribe with one click.

Try the tools

Real tools from the course, each on the lesson page that explains it.

Bedtime calculator

Enter the time you need to get up and how long you take to fall asleep; it counts back to a lights-out window.

Try it →

7-day sleep diary

Log a night in about 2 minutes. It works out your time asleep, sleep efficiency and weekly averages.

Try it →

Caffeine timeline

Slide to the time of your last coffee and see roughly how much caffeine is still in your body at bedtime.

Try it →

1-minute alertness test

A reaction-time game based on a research test. Run it morning and evening and compare. Not a medical test.

Try it →

What you learn, module by module

One new module every Tuesday. Module 1 of 8 is open.

  1. Module 1: Your sleep, right now · open →
    How much sleep you need, why time in bed is not time asleep, sleep debt, and your own starting point: diary, alertness, caffeine and body-clock checks.
  2. Module 2: Your two sleep switches · coming soon
    The body clock and sleep pressure, using light as a reset, and your own caffeine cut-off.
  3. Module 3: A night, mapped · coming soon
    Sleep stages and cycles, why deep sleep comes early and REM later, and why brief wake-ups are normal.
  4. Module 4: What sleep does for you · coming soon
    What the evidence says about sleep and memory, mood, immunity and metabolism; pick your week-2 experiment.
  5. Module 5: Build a better night · coming soon
    Light, caffeine, alcohol, exercise, food, the bedroom and naps, and a wind-down that suits you.
  6. Module 6: Out of sync · coming soon
    Jet lag, shift work, teenage body clocks, social jet lag and clock changes; plan light and sleep for a trip or a rota.
  7. Module 7: When sleep goes wrong · coming soon
    Insomnia and what helps, the signs of sleep apnoea and other disorders, and when to see a doctor.
  8. Module 8: Sleep for life: your plan · coming soon
    How sleep changes with age, your end-of-course self-check, and a written sleep plan built from your own data.

Your course map

Your badges

Get each new module by email

Module 2 opens on Tuesday 6 October. One short email when each module opens, with the link. No spam; unsubscribe with one click.