SankeyDiagram.net

SankeyDiagram.net is a free, open‑source online Sankey diagram maker that runs in your browser with no sign‑up, keeping your data 100% local and private. Create Sankey charts from plain‑text using the simple syntax, with customizable colors and layout, auto-calculating operators, and support for basic math expressions. Ideal for visualizing personal-finance budgets, cash flow, energy or material flows, and user journeys, it also lets you export diagrams as PNG, SVG, text, or a shareable link.