Online Tool Store
Sankey Diagram Maker
Enter flows as source, target, and value rows to render a Sankey diagram showing how a quantity splits and moves between stages, as downloadable SVG.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
How Sankey Diagram Maker works
- List flows as
source,target,valuerows — a sample signup funnel is pre-filled and rendered immediately. - Every stage named in the rows becomes a node. Each node's column is one step after its deepest source, so the diagram automatically reads left to right in dependency order — no manual layout needed.
- Within a column, nodes are stacked in proportion to their total flow, and each connecting ribbon's thickness is scaled the same way, so the width of a band always represents its share of the total.
- Hover a ribbon to see the exact source, target, and value as a tooltip; edit the textarea and the diagram redraws live.
The layout is a simplified version of the same node-ranking approach real Sankey libraries use: a node's rank equals one more than the maximum rank of any node that feeds into it, and vertical position within a rank is proportional to total flow.
FAQ
How do I add a new stage to the diagram?
Add a row using that stage's name as the source or target — the tool discovers nodes from the rows themselves, so there is no separate list of stages to keep in sync. A node with no incoming flow is placed in the leftmost column automatically.
Why is a flow's ribbon a certain thickness?
Ribbon thickness is proportional to the value in that row relative to the largest total at any single stage, the same convention real Sankey diagrams use — a bigger number produces a visibly thicker band, so the biggest drop-off or contributor is obvious at a glance.
Can values not balance between stages?
Yes — a node's outgoing total does not have to exactly equal its incoming total. That is normal for something like a funnel with drop-off ("Bounced") alongside forward progress ("Signed Up"): the sample data above splits visitors into both.
How we compare
| Feature | Online Tool Store | Doing it manually | A generic online tool |
|---|---|---|---|
| No file upload — runs in your browser | ✓ | N/A | ✗ |
| No sign-up required | ✓ | ✓ | ✗ |
| Free, no watermark | ✓ | ✓ | ✗ |
Most Sankey generators require a spreadsheet upload and a rendering queue, or a charting-library account. This tool parses plain-text rows and draws the diagram as inline SVG the moment you stop typing — nothing leaves your browser.