How to use the habit tracker
- New habit name: type a habit such as Drink water and press Add habit. You can track up to 20 habits, with names up to 60 characters.
- Tap a square to mark that day done, and tap it again to undo. The grid shows the last five weeks from Sunday to Saturday, and today has a blue outline. With a keyboard, Tab to a grid, move with the arrow keys and press Space.
- Read the line under each habit: current streak, best streak and how many of the last 7 days you checked off. The blue box adds all habits together.
- Rename keeps every check mark, Delete removes a habit, and Undo in the yellow bar restores it.
How the numbers are counted
Streak is the number of days in a row, ending today, with a check mark. If today is unmarked the count starts from yesterday, so your chain is not broken until the day is over. Best is the longest run in your saved history, including days older than the five weeks on screen. Last 7 days is today plus the six days before it, and completion is check-ins divided by habits times 7, rounded to a whole percent. Days follow your device's local calendar, so a day rolls over at your midnight.
The method is called "don't break the chain." It comes from comedian Brad Isaac's story of advice he says Jerry Seinfeld gave him: mark an X on a calendar every day you do the work. Seinfeld has not confirmed it, so treat it as a story. See James Clear's account.
Worked example
On first load you see Exercise and Read 20 min with empty squares, and the box reads Today: 0 of 2 habits done and Last 7 days: 0 of 14 check-ins done (0% completion). Tap today's square for Exercise and its line becomes Streak: 1 day · Best: 1 day · Last 7 days: 1 of 7, while the box reads Today: 1 of 2 habits done and Last 7 days: 1 of 14 check-ins done (7% completion). Tap the two days before today as well and the streak reads 3 days, with 3 of 14 check-ins (21%).
Limits and edge cases
- Habits live in this browser's local storage and do not follow you to another device. If storage is blocked the tracker still works until you close the page, and it shows a warning.
- You can mark or undo any day in the five weeks shown, up to today. Older marks are kept and still count toward streaks.
- To count a number each day, use the tally counter. For one-off jobs use the online to-do list, and to protect time for the habit itself try the focus timer.
Frequently asked questions
How long does it take to build a habit?
In a 2010 study of 96 volunteers, the median time to reach a stable habit was 66 days, with individuals ranging from 18 to 254 days. That is longer than the 21 days often quoted, so keep the chain going until the behavior feels automatic.
What happens to my streak if I miss a day?
Once a full day passes without a check mark, the streak drops to 0 and restarts the next day you mark. Your best streak and earlier check marks stay. In the study below, one missed day had little effect on later habit strength.
Where are my habits saved?
In this browser on this device, and nothing is sent to a server. There is no sync or export, so a second device starts empty and clearing your site data erases your habits. Take a screenshot if you want a record.
Source: Lally, van Jaarsveld, Potts and Wardle (2010), How are habits formed: Modelling habit formation in the real world, European Journal of Social Psychology 40(6), summarised by the BPS Research Digest.