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Sankey Visualizer
Free Flow Diagram Maker
Free · No Coding · No Signup

Free Sankey Diagram Maker Online
No Coding Required

Create Sankey charts and alluvial diagrams directly in your browser — no installation, no account, no cost. Paste your CSV data and get a polished flow diagram in seconds with six styles and high-resolution export.

Your data never leaves your browser — nothing is sent to any server
6
Flow styles
10
Color palettes
PNG resolution
Canvas size

Built for Every Kind of Flow

Any dataset with a source, target, and value can be turned into a Sankey diagram.

Energy & Power Systems

Visualize electricity generation, transmission losses, fuel consumption, and renewable energy flows across entire grids or single facilities.

Personal Finance & Money Flow

Map where your money comes from and where it goes. Budget breakdowns, revenue streams, salary allocation, and cash flow — visualized as a money flow diagram.

Supply Chains

Track material flows from raw inputs through processing and distribution to final products. Identify inefficiencies and bottlenecks at a glance.

Environmental & Carbon

Quantify greenhouse gas emissions, carbon flows, water usage, or waste streams across processes, industries, and supply chains.

Conversion Funnels & User Journeys

Visualize conversion funnels, drop-off points, and traffic sources. See exactly how users move through websites, apps, or sales pipelines — step by step.

Research & Academia

Present data flows, experimental results, or system analyses in publications and presentations with publication-quality SVG exports.

Everything You Need, Nothing You Don't

A full-featured Sankey diagram tool that runs entirely in your browser.

6 Flow Styles
Bundled, curved, straight, orthogonal, tapered, S-curve
Drag & Reposition
Move nodes freely, fine-tune label positions
Smart Optimization
Auto-minimizes crossing flows for cleaner diagrams
PNG & SVG Export
High-resolution raster and scalable vector output
Custom Colors
Per-node colors, 10 palettes, dark & light mode
No Signup Needed
Open the page and start building — completely free
Save Projects
Save and reload your diagrams as .sankey project files
Flow Labels
Label flows by value, name, or both — inline or offset
100% Private
Your data stays in your browser — nothing is sent to any server

Get Your Diagram in Three Steps

No learning curve. Your first diagram takes under a minute.

01
Step 01

Paste Your Data

Enter rows of Source, Target, Value in the data panel — or upload a CSV or Excel file. Try one of the built-in examples to see the tool in action immediately.

02
Step 02

Customize the Look

Choose from six flow styles, ten color palettes, multiple font options, and layout controls. Drag nodes to perfect the arrangement or use smart optimization.

03
Step 03

Export & Share

Download a high-resolution PNG for slides and reports, or an SVG vector file for infinite scaling. Save the project to continue editing later.

Simple CSV Format

Each row defines one flow. Three columns: where the flow starts, where it ends, and how much. That's all. Tab-separated and Excel files are also accepted.

Optional fourth column for a custom label. Headers are auto-detected and skipped.

Source, Target, Value
Solar, Grid, 450
Wind, Grid, 280
Grid, Residential, 310
Grid, Industrial, 290
Grid, Losses, 130

Frequently Asked Questions

Common questions about Sankey diagrams and this tool.

What is a Sankey diagram?

A Sankey diagram is a type of flow chart where the width of each arrow or band is proportional to the quantity it represents. Originally used to visualize steam engine efficiency, they are now widely used for energy audits, financial reporting, environmental assessments, and any situation where quantities flow between nodes.

How do I create a Sankey diagram?

Enter your data as comma-separated values with three columns: Source, Target, and Value. Each row represents one flow — for example "Solar,Grid,450". The tool builds the diagram instantly. You can then drag nodes, change colors, switch flow styles, and export when ready.

Is this tool free? Do I need an account?

Completely free, no account required. There are no watermarks on exports, no usage limits, and no ads within the tool. Just open the page and start creating.

What file formats can I export?

PNG at up to 4× resolution for presentations and documents, and SVG vector format for lossless scaling and further editing in tools like Illustrator, Figma, or Inkscape. You can also save the full project as a .sankey file and reload it later.

How is this different from other Sankey tools?

Most online Sankey tools are basic — limited styles, no drag-and-drop, fixed layouts. This tool offers an infinite canvas, six flow rendering styles, smart crossing optimization, per-node color overrides, flow labels, annotations, a project save system, and high-quality SVG export. It is designed for researchers, engineers, and analysts who need more control.

Can I use it for energy flow diagrams?

Yes — energy flows are one of the most common use cases. Whether you are mapping national energy consumption, building energy audits, power grid flows, or fuel chain analysis, the proportional flow widths make quantities immediately comparable.

Ready to build your diagram?

Free, browser-based, and ready in seconds.

Built by Haider Niaz. Free for everyone — researchers, engineers, students, and analysts.