Why heatmaps work for habits
A habit heatmap shows a whole year at once, one square per day, darker for more. Add a habit, click a day to log it, click again for a stronger shade, or press and drag across days to paint a whole run. Prefer real numbers? Switch a habit to value mode and log minutes, pages or kilometres; shades scale to your own data. View the last 12 months or any calendar year, switch to a year-in-pixels layout with months as columns, and combine every habit into one overview. Streaks, consistency, weekly-goal weeks, monthly totals and your strongest weekdays update as you go, and a high-resolution PNG makes it easy to share.
GitHub's contribution graph made a whole year of activity visible in one glance, and the same view works for any habit. Long runs of colour are motivating, gaps are honest, and seasonal patterns jump out in a way a list of check-ins never shows. It's the visual version of the “don't break the chain” method: the chain is right there on the screen.
