Habit Tracker

Features

• Unlimited habits with a streak grid each
• Current streak and longest streak
• Completion percentage over the visible period
• 30, 60 or 90-day views
• Data stays on your device

How to use it

1. Add a habit you want to build.
2. Click today's square when you complete it.
3. Watch the streak build across the grid.
4. Export the data if you want to keep it.

What the research actually says about habits

The widely repeated claim that habits take 21 days comes from a misreading of a 1960 book by a plastic surgeon, who observed that patients took about 21 days to adjust to a changed appearance. The actual research is less tidy: a 2009 study by Phillippa Lally at UCL found habits took a median of 66 days to become automatic, with a range from 18 to 254 days depending on the person and the complexity of the behaviour.

The same study found something more useful than the number. Missing a single day had no measurable effect on eventual automaticity. The all-or-nothing framing that a broken streak ruins everything is not supported by evidence, and it is actively counterproductive if it causes people to abandon a habit after one lapse. The grid here shows longest streak alongside current streak partly for this reason.

What does reliably help is making the behaviour easy to start and tying it to an existing routine. Implementation intentions, deciding in advance exactly when and where you will do something, roughly double follow-through in controlled studies. Tracking itself helps too, but mostly through attention rather than motivation: a visible record makes the gap between intention and behaviour hard to ignore.