Financial statements and budgets
Show how revenue is allocated across costs, operating profit, tax and retained income, or explain how a budget is distributed among programmes.
Free Sankey Diagram Maker
Create professional Sankey diagrams directly in your browser. Add flows, customise the design, and export PNG, SVG or JSON.
Free No signup Diagram data stays in your browser.
Tip: Click a flow to change its value or colour. Click a node label to change node and label colours. Drag nodes to move them.
Export diagram
Files are created locally in this browser.
How to create a Sankey diagram
You can move from raw flow values to a finished diagram in three practical steps. The editor updates the preview as you work, so you can check the structure before exporting.
- Enter your flows. Add each source, target and value. A source is where a quantity begins, a target is where it goes, and the value controls the width of the connecting band.
- Customise the presentation. Adjust the layout, labels and colours, add a chart title and subtitle, and drag nodes within their flow layers when the automatic arrangement needs refinement.
- Export the result. Download PNG for presentations and documents, SVG for scalable design work, or JSON to save an editable diagram file for later.
What is a Sankey diagram?
A Sankey diagram is a flow visualisation in which band width represents the quantity moving between nodes. Wider bands carry more of the measured value, making the relative scale of each route easy to compare. The format is especially useful when a total splits into several destinations, passes through intermediate stages, or combines from multiple sources.
Sankey diagrams highlight distribution, transfers and losses that can be difficult to see in a table. They are sometimes called Sankey charts, but the same principle applies: each connection shows where a quantity came from, where it went and how much moved.
Popular Sankey diagram uses
Energy allocation
Trace energy from generation sources through conversion and consumption, with losses shown alongside useful output.
Customer journeys and funnels
Compare how visitors move through acquisition channels, product stages and conversion outcomes without reducing every journey to one linear funnel.
Supply chains
Map goods or capacity from suppliers through facilities, transport routes and destinations to expose concentration and hand-offs.
Material flows
Visualise raw materials, manufacturing inputs, reuse, waste and recycling in environmental or operational analysis.
Private, browser-based diagram editing
Diagram content and imported files are processed locally by the CreateSankey editor. The current draft may be retained in your browser so that you can continue after refreshing or returning on the same device. There is no CreateSankey upload API or account database for diagram content, and no signup is required.
Because the editor runs in the browser, you choose when to create a local export or import a saved JSON file. If you are automating diagram creation, the AI agent JSON guide explains the supported contract, and the CreateSankey JSON Schema provides a machine-readable definition.
Frequently asked questions
Is CreateSankey free?
Yes. You can build, edit and export diagrams with the browser editor for free.
Do I need to sign up?
No. There is no account requirement, so you can begin with the built-in example or a blank diagram immediately.
Is my diagram content uploaded?
No. Diagram editing, validation, imports and exports are handled in your browser rather than by a CreateSankey diagram-upload service.
What input structure does the editor expect?
Each flow needs a source node, a different target node and a positive numeric value. The full JSON format can also store titles, colours, layout preferences, node positions and optional source attribution.
Which export formats are available?
Export PNG for a raster image, SVG for a scalable vector, or JSON for a portable diagram file that can be imported and edited again.