Sankey Chart

Free Online Sankey Chart Maker

What is a Sankey Chart?

A Sankey chart visualizes how quantities flow between connected nodes, where the width of each link is proportional to the volume it carries. They're ideal for revealing where the largest transfers, losses, or concentrations occur within a system. Use them to map energy flows, trace budget allocations, or follow users through a multi-step journey — any time the relative size of flows tells the real story.

Key Features

1

Flow-Width Encoding

Link widths scale automatically with flow values, so dominant paths are instantly visible without reading labels.

2

Multi-Stage Flows

Show how a quantity splits, recombines, or shrinks across as many stages as your data requires.

3

Node & Link Customization

Assign custom colors to nodes, control label placement, and adjust link opacity to keep the diagram readable.

4

Inline Value Labels

Display exact flow values on each link so stakeholders can read precise numbers alongside the visual proportions.

5

Auto Layout

Nodes are positioned automatically to minimize link crossings and keep the diagram clean with no manual arrangement needed.

6

Color Schemes

Choose per-node colors to group by category, or use gradient flows to trace individual paths across stages.

Best For

Energy and resource allocation analysis
Website traffic and user journey mapping
Budget flow and cost breakdown reporting
Supply chain and material flow tracking
Revenue attribution across marketing channels
Process efficiency and loss identification

When to Use

  • When a total quantity splits into multiple destinations across stages
  • When the relative size of flows matters as much as the individual values
  • When you want to pinpoint where the biggest transfers or losses occur
  • When tracing inputs through a process to show what reaches the output
  • When comparing how multiple sources contribute to multiple outcomes
  • When a plain table of flows is too hard to read at a glance

Common Mistakes

  • !
    Adding too many nodes — diagrams with more than 15–20 nodes become unreadable
  • !
    Using flows that don't balance (inputs don't equal outputs), which misleads readers
  • !
    Labeling every thin flow when narrow links can't fit readable text
  • !
    Mixing unrelated flow types in one diagram, blurring the message
  • !
    Ignoring flow direction, leaving readers unsure which way quantities move
  • !
    Choosing colors at random instead of grouping related nodes visually

Free Online Sankey Chart Maker

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