Free Sankey Diagram Maker

Free Sankey Diagram Maker turns a plain-English description into a Sankey diagram you can export, share, or drop straight into your docs. No drawing tools, no syntax cheat-sheets — just describe what you need and get a clean Mermaid-compatible diagram back.

What is a Sankey diagram?

A Sankey diagram visualises flows of quantity between nodes. Flow width is proportional to the amount moved, so you can see at a glance where the big pipes are and which paths account for most of a total.

Sankey diagrams are the right tool for energy flows, budget allocations, funnel analyses, traffic-source attributions, and any scenario where you want to follow "where did all the X go?" across multiple stages.

Who uses Sankey diagrams?

• Analysts visualising conversion funnels and attribution
• Growth engineers tracing user flow across activation stages
• Finance teams showing budget allocation across departments
• Energy and sustainability analysts modelling energy flows
• Product managers visualising feature-usage and churn paths
• Operations teams tracing materials and process flow
• Consultants presenting value-chain or supply-chain analyses
• Researchers reporting multi-stage data aggregations

Why generate Sankey diagrams with AI?

Sankey diagrams are powerful and a pain to author. The nodes, the links, the exact flow values — producing one in D3.js or Plotly takes non-trivial code, and spreadsheet tools rarely support them well.

Generating a Mermaid Sankey from a plain description ("500 visits total, 300 to home, 150 to pricing...") collapses the overhead to one paragraph of prose. Great for monthly reports, blog posts, and dashboards that need a one-off visual.

How to use the Free Sankey Diagram Maker

1. Describe the flows — source node, target node, and the quantity flowing between them — for each link.
2. Paste the description into the Free Sankey Diagram Maker prompt box and click Generate.
3. Review the rendered diagram; request tweaks like "split Checkout into Success and Failure" or "roll up the small flows into Other".
4. Export as SVG, PNG, or Mermaid source for your funnel report, attribution deck, or budget memo.
5. Save it so updating with next month's numbers is a five-second regenerate.

FAQ

How many nodes can a Sankey handle?

Mermaid handles a few dozen nodes gracefully. Past that, consider aggregating long-tail nodes into an "Other" bucket — readability drops fast beyond ~20 distinct nodes.

Do the flows need to balance?

Not strictly — you can show loss, drop-off, or unallocated flow by having outflows smaller than inflows at a node. Mermaid renders the imbalance visibly, which is usually what you want.

Can I colour flows by category?

Mermaid Sankey uses the theme palette; per-flow colour customisation requires post-export SVG editing. For rich per-flow styling, consider a D3.js implementation.