Five free plans · 21 days each · open beta
21 days. One change. Your own chart.
Example: day 8 of 21
Pick one plan. Do up to three small habits a day. See what changed against your own first days.
Free during the open beta. No card. How lifetime places work
Five plans. Pick one.
21 days each. All free during the open beta.
Up to three small habits a day.
The app shows today’s habits. Tick them off. That is the whole job.
Up at your wake-up timeSame time every day done
Caffeine cutoff8 hours before bed not done yet
Bed is for sleepAwake in bed? Get up not done yet
Evening wind-downOptional · 10 min optional
Magnesium add-onOptional · starts today optional
MoodCalm done
A sample day for a made-up person called Maya.
- Up to three required habits a day.
- Optional extras you can skip.
- Supplements are never required.
- Miss a day and it stays missed. Nothing resets.
Say how you feel. Seven moods.
- optimistic Friendly
- angry Passionate
- happy Loving
- enthusiastic Energetic
- balanced Renewed
- focused Creative
- peaceful Calm
Choose your wake-up timeset-up set-up, day 1
Choose your caffeine cutoffset-up set-up, day 1- Up at your wake-up time required, days 2 to 21
- Caffeine cutoff required, days 2 to 21
- Bed is for sleep required, days 3 to 21
- Evening wind-downoptional optional, days 5 to 21
- Magnesium add-onoptional · never required optional, days 8 to 21
Why these habits
- Up at your wake-up time A fixed wake-up time is part of CBT-I, the first treatment recommended for long-term insomnia. Clinical guideline · AASM guideline, 2021
- Caffeine cutoff Caffeine six hours before bed still disrupted sleep in a lab study. A review suggests about 8.8 hours. Small trial; meta-analysis · Drake et al., 2013; Gardiner et al., 2023
- Bed is for sleep Leaving bed when you can’t sleep is a recommended part of CBT-I. Clinical guideline · AASM, 2021; Furukawa et al., 2024
Measured against you.
Not a stranger’s average.
Still forming until day 14
Example data for a made-up person: sample data, not a result anyone got. A trend in one person’s own data, not a diagnosis. Early results say still forming until day 14 (our rule, not a study).
Health connections are optional: Apple Health on iPhone, Health Connect on Android, and Oura in the app on either phone.
- Apple Health
- Health Connect
- Oura
After seven days, a short look back.
Keep going or stop. Stopping never counts against you.
Write a plan for your clients.
Build it in Creator Studio on the web. Clients follow it in the app, free. Paid selling is not live.
For coaches200 lifetime places
Free while the beta lasts.
- Now
- Every feature is free during the open beta. No card. No end date has been set.
- A lifetime place
- Finish your first full 21-day plan during the beta with at least 80% of its required habits done and, if fewer than 200 people have qualified before you, Explorer is yours for life straight away.
- Stopped early?
- It doesn’t count against you. The first plan you run to its end is the one that counts.
- Places claimed
- 1 of 200 · read live from our server
- After the beta
- One active plan, daily habits, mood, recaps and your history stay free. Explorer, the paid tier, adds every plan and connected health readings.
- Medical
- By Day is not a medical device and does not diagnose or treat any condition. Talk to a clinician about symptoms, or before changing treatment.
Questions people ask
More answers in SupportWhat is By Day?
By Day is an app for short self-experiments: one change, run as a 21-day plan. Do up to three small habits a day, then review how you felt and any connected health readings against your own baseline. A trend can help you decide what to keep; it does not prove what caused a change.
What is a plan?
A plan is three weeks built around one goal, such as falling asleep faster or walking more. It has a start and a finish, up to three required habits a day, optional extras you can skip, a week-one check-in and a recap at the end.
Do I need a wearable?
No. You can follow any plan and log your habits without one. Connecting Apple Health, Health Connect or Oura adds health readings, which gives By Day more to compare against your baseline.
How much time does it take each day?
It depends on the plan, and every plan shows its daily time before you start. Many habits take a few minutes; the walking plan has longer walks. Habits are not locked to a time of day.
What is included during the beta?
The open beta is running and has no end date yet. Every feature is free: every plan, connected health readings, home screen widgets, offline habit logging, recaps and your full history. No card is needed.
What happens after the beta ends?
Your account and history stay. The free tier lets you run one active plan at a time. Explorer, the paid tier, adds every plan and connected health readings. Finish your first full 21-day plan during the beta with at least 80% of its required habits done and, if fewer than 200 people have qualified before you, Explorer is yours for life straight away. A plan you stop early doesn't count against you; the first one you run to its end does.
Where can I use By Day?
By Day is available for iPhone on the App Store and for Android on Google Play. Use the app to run plans, log your habits and connect health readings. Creators write and publish plans in Creator Studio on the web.
Is my health data private?
Your account starts private. You choose which health categories By Day can read and can change those permissions on your device. Health data is not sold or used for advertising. You can delete your account and its data from Settings.
What if I miss a day?
The plan keeps going. A missed habit stays visible instead of resetting your progress, and the recap shows it, because it helps explain how much weight to give the result.
Can I change plans partway through?
Yes. Starting a new plan ends the current one, and By Day asks you to confirm first. The days you completed stay in your history with a recap.
Start a 21-day plan.
Choose one on your phone. The first day is mostly set-up.
Occasional updates
Hear when a new plan ships.
A short note when a new plan or a meaningful change is ready. One confirmation email first, and no spam.