How do I create a sankey chart in JavaScript?

Install with `npm install katucharts.js`, then call KatuCharts.chart(container, { chart: { type: 'sankey' }, series: [...] }).

Why does my sankey chart render as a line chart?

The chart type was not registered. KatuCharts logs "KatuCharts: unknown series type " ", falling back to line" and draws a line chart rather than throwing. Import the module the type belongs to — for example `import 'katucharts.js/bio';` — before creating the chart.

Why do I get "Cannot read properties of null (reading 'appendChild')"?

The container element does not exist when the chart is created. Create the chart after the element is in the DOM: in React that means inside useEffect, not during render.

Why is the chart rendering with zero height?

The container has no height. A div with no content collapses to zero. Give it a height in CSS, or pass `chart: { height: 400 }` in the options.

Flow

Sankey

type: 'sankey'

Flow diagram showing quantities between nodes. Nodes are created implicitly from the from/to fields.

Edit the JSON on the right and press Run (or ⌘/Ctrl + Enter) — data, titles, categories and colors all update live.

Live

Sankey

Edit · JSON

Data format

{ from: string, to: string, weight: number }

Data shape

The JSON you pass inside the chart — drop it straight into your series.

data: [
  { from: 'Homepage', to: 'Products', weight: 800 },
  { from: 'Homepage', to: 'Blog', weight: 300 },
  { from: 'Products', to: 'Cart', weight: 500 }
]

Example

import KatuCharts from 'katucharts.js';

KatuCharts.chart('container', {
  chart: { type: 'sankey' },
  series: [{
    data: [
      { from: 'Homepage', to: 'Products', weight: 800 },
      { from: 'Homepage', to: 'Blog', weight: 300 },
      { from: 'Products', to: 'Cart', weight: 500 }
    ]
  }]
});

Type-specific options

Option	Description
`nodeWidth / nodePadding`	Node bar width (20) / vertical spacing (10).
`linkOpacity / linkColorMode`	Link opacity (0.5) / 'from' \| 'to' \| 'gradient'.
`curveFactor / levels`	Link curvature / per-depth configuration.

Variations

Gradient links

linkColorMode: 'gradient' blends each link from its source to its target color.

KatuCharts.chart('container', {
  chart: { type: 'sankey' },
  series: [{
    linkColorMode: 'gradient',
    data: [
      { from: 'Home', to: 'Products', weight: 800 },
      { from: 'Products', to: 'Cart', weight: 500 }
    ]
  }]
});

Common errors

Why does my sankey chart render as a line chart?: The chart type was not registered. KatuCharts logs "KatuCharts: unknown series type "<type>", falling back to line" and draws a line chart rather than throwing. Import the module the type belongs to — for example `import 'katucharts.js/bio';` — before creating the chart.
Why do I get "Cannot read properties of null (reading 'appendChild')"?: The container element does not exist when the chart is created. Create the chart after the element is in the DOM: in React that means inside useEffect, not during render.
Why is the chart rendering with zero height?: The container has no height. A div with no content collapses to zero. Give it a height in CSS, or pass `chart: { height: 400 }` in the options.

FAQ

How do I create a sankey chart in JavaScript?: Install with `npm install katucharts.js`, then call KatuCharts.chart(container, { chart: { type: 'sankey' }, series: [...] }).
Why does my sankey chart render as a line chart?: The chart type was not registered. KatuCharts logs "KatuCharts: unknown series type "<type>", falling back to line" and draws a line chart rather than throwing. Import the module the type belongs to — for example `import 'katucharts.js/bio';` — before creating the chart.
Why do I get "Cannot read properties of null (reading 'appendChild')"?: The container element does not exist when the chart is created. Create the chart after the element is in the DOM: in React that means inside useEffect, not during render.
Why is the chart rendering with zero height?: The container has no height. A div with no content collapses to zero. Give it a height in CSS, or pass `chart: { height: 400 }` in the options.

Common options (color, visible, marker, dataLabels, animation, events, zones…) apply to every type — see Configuration → series. See it rendered in the gallery.