How to read a habit heatmap
The year in 365 squares. Four patterns show up in almost everyone, and each one means something specific.
The contribution graph shape borrowed from GitHub turns out to be the best single view of a habit, because it shows a year without asking you to read a number. Density means frequency, gaps mean absence, and the eye finds the pattern before you have consciously looked for it.
Four patterns show up again and again. Vertical stripes, where two columns of the week are pale and five are dark, which is the weekday and weekend split. Horizontal bands, where a whole run of weeks is dense and then a run is empty, which is usually a life event rather than a motivation problem. Fading, where the left of the grid is dark and the right is grey, which is the slow abandonment almost everyone experiences at least once. And speckle, where the squares are scattered with no structure, which nearly always means the habit has no cue.
Each of those points at a different fix, which is why the picture is worth more than the streak number sitting above it. Speckle is a cue problem. Fading is a target problem. Bands are usually nothing at all and should be left alone.
This page covers how the colour scale is built and why it lies if you set it wrong, the four patterns with real examples, what a healthy grid actually looks like (not solid), and how to export one without giving your data to a website.
Outline
Status: outline. The introduction above is finished copy. Everything below is the section plan for the full draft, targeted at about 1 800 words.
- What the grid encodes. 53 columns, 7 rows, and where the week starts.
- The colour scale. Linear, quantile and capped, and how a bad scale flatters you.
- Pattern one: vertical stripes. Weekday bias, and what size is normal.
- Pattern two: horizontal bands. Life events, and why they usually need no fix.
- Pattern three: fading. Slow abandonment, caught early.
- Pattern four: speckle. The missing cue, and the fastest fix.
- What a healthy grid looks like. Not solid, and why solid is a warning sign.
- Exporting one. Making an image locally, and what the free tool does.