Sankey link (flow)
A link is a band in a Sankey diagram that carries an amount from one node to another. Its width is the amount it carries, so the eye compares quantities by comparing widths. Charting libraries call it a link; most readers call it a flow. They are the same thing.
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Open the editor and type your nodes one per row, with where each one flows and how much. The diagram draws itself as you type. Your work is saved automatically in your browser.
Create Your Sankey Diagram FreeWhat a link records
Every link is three facts: where it starts, where it ends, and how much it carries. That is why Sankey data is so often a three-column table (source, target, value), one row per link. In SankeyCharts.app you can type those three facts into the sheet row of the starting node, or paste the table and let the editor build the links.
Direction, colour and labels
Links read left to right, from earlier stages to later ones. Colour does not change the amount; it groups. A common choice is to colour a link by the node it leaves, so the reader can follow one source across the diagram. A flow label puts a word on the band itself, useful when the band means something its two nodes do not say.
Links that go backwards
Sometimes an amount returns upstream: a returned order, a retried payment, recycled material. Drawn as an ordinary band it would cross the whole diagram and tangle the columns, so SankeyCharts.app draws a link that goes back upstream as a return line under the diagram, where it stays visible without hiding the forward flows.
Common mistakes
- A link with no amount, which has no width to draw (the editor shows it dashed until it has one)
- A node linked to itself, which a Sankey cannot draw
- Two links for the same pair of nodes, which should usually be one link with the summed amount
- Amounts in different units on the same diagram, which makes the widths meaningless
Frequently asked questions
What is a link in a Sankey diagram?
The band that carries an amount from one node to another. Its width shows the amount, so wider bands are larger flows.
Why are Sankey links different widths?
Width is the amount. A link carrying twice as much is drawn twice as wide, which is what lets a reader see where most of the total goes at a glance.
Can a Sankey link go backwards?
It can, for amounts that return upstream. Most tools draw it as a loop; SankeyCharts.app draws it as a return line under the diagram so the forward flows stay readable.
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The editor opens with a starter Sankey diagram. Type your own nodes and amounts, and the diagram rebuilds itself as you type. No signup required to get started.
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