What is the best free Sankey diagram generator?

ConceptViz offers a free AI-powered Sankey diagram generator that creates professional-quality flow visualizations in seconds. Simply describe your data flows, select a visual style and flow type, and the AI generates a proportionally accurate Sankey diagram ready for research papers, presentations, and reports.

When should I use a Sankey diagram instead of a bar chart or pie chart?

Use a Sankey diagram when you need to show how quantities flow, split, or merge between stages. Bar charts compare discrete values, and pie charts show parts of a whole, but neither reveals the directional movement of resources. Sankey diagrams are ideal for energy audits, budget allocation tracking, material flow analysis, and any multi-stage process.

How do I read a Sankey diagram?

In a Sankey diagram, nodes represent stages or categories, and the bands connecting them represent flows. The width of each band is proportional to the quantity it carries. Follow the bands from left to right to trace how inputs are distributed across outputs. Wider bands indicate larger flows, so you can quickly identify the dominant pathways.

Can I use Sankey diagrams in academic research papers?

Absolutely. Sankey diagrams are widely published in journals across energy science, environmental engineering, clinical medicine, and economics. They are particularly common in life cycle assessments, material flow analyses, and clinical trial CONSORT flow diagrams.

How many nodes and flows should a Sankey diagram have?

For clarity, keep your Sankey diagram to 5-15 nodes and no more than 20-25 flow bands. Research shows that diagrams with more than 7-8 major flows become difficult to interpret. If you have many small flows, consider grouping them into an "Other" category.

What data do I need to create a Sankey diagram?

At minimum, you need source-target pairs with associated quantities. For example: "Energy production to Transportation: 30 units, Energy production to Industry: 45 units." You can also simply describe the process in plain text and our AI will infer reasonable proportions.

For Science & Engineering

Sankey Diagram Generator AI-Powered

Describe your data flows and our AI will create a professional Sankey diagram with proportional band widths. Perfect for energy audits, material flow analysis, research papers, and presentations.

Proportional Flow WidthsMultiple Flow TypesPublication-Ready QualityScientific & Modern Styles

Sankey Diagram Generator

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Sankey Diagram Examples

Browse scientific and engineering examples or generate your own above

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Energy Flow in Ecosystem

Ecosystem energy flow Sankey diagram illustrating how energy transfers and diminishes across trophic levels.

ecologyenergy-flowtrophic-levels

Research Funding Allocation

Research funding Sankey diagram showing the allocation of grants from funding bodies through universities to research departments.

fundingresearchallocation

Material Flow Analysis

Industrial material flow analysis Sankey diagram tracking raw materials through manufacturing processes to finished products and waste.

industrialmaterial-flowmanufacturing

Patient Flow in Clinical Study

Clinical trial patient flow Sankey diagram visualizing participant progression from screening through treatment arms and endpoints.

clinical-trialpatient-flowmedical

Carbon Emissions Flow

Carbon cycle Sankey diagram mapping greenhouse gas emissions from source sectors through atmospheric processes to carbon sinks.

carbonemissionsclimate

Supply Chain Resource Flow

Supply chain Sankey diagram tracking resources from raw material suppliers through processing, distribution, and retail to consumers.

supply-chainlogisticsresources

What is a Sankey Diagram?

A Sankey diagram is a flow visualization where the width of each arrow or band is proportional to the quantity it represents. Originally developed by Captain Matthew Sankey in 1898 to visualize energy efficiency in steam engines, these diagrams have become essential tools in science, engineering, and data analysis. Sankey diagrams excel at showing how quantities split, merge, and flow between stages in a process.

Why Use Sankey Diagrams in Research?

Visualize energy transfers and losses across system components with proportional flow widths
Track material flows through industrial processes to identify waste and inefficiency
Map patient progression through clinical trial phases from enrollment to outcomes
Illustrate carbon emissions pathways from source sectors to atmospheric accumulation
Communicate complex multi-stage processes to reviewers and non-specialist audiences
Reveal hidden patterns in resource allocation that tables and bar charts cannot show

Types of Sankey Diagrams

Sankey diagrams serve different analytical purposes depending on the domain. Energy Sankey diagrams map energy inputs, conversions, and losses across systems such as power plants or buildings. Material Flow Analysis (MFA) Sankey diagrams track the mass of substances through production, use, and disposal stages. Cost and budget Sankey diagrams visualize how financial resources are allocated from revenue sources to expenditure categories.

How to Create Effective Sankey Diagrams

Start by defining your source nodes (inputs) and target nodes (outputs), then quantify the flow between each pair. Limit visible paths to 7-8 key flows to avoid visual clutter. Use color purposefully: gradient coloring can show flow direction, while categorical colors distinguish different resource types. Always label nodes clearly and include units so readers understand the scale.

Applications in Science and Engineering

Ecology: mapping energy flow through trophic levels and nutrient cycling in ecosystems
Chemical engineering: tracking mass and energy balances in reactor systems and refineries
Environmental science: visualizing water usage, carbon footprints, and waste management flows
Healthcare: illustrating patient pathways, treatment outcomes, and hospital resource utilization
Urban planning: analyzing transportation flows, electricity distribution, and city metabolism
Economics: depicting trade flows, supply chains, and national resource consumption patterns

Frequently Asked Questions

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What is a Sankey Diagram?

Why Use Sankey Diagrams in Research?

Visualize energy transfers and losses across system components with proportional flow widths

Track material flows through industrial processes to identify waste and inefficiency

Map patient progression through clinical trial phases from enrollment to outcomes

Illustrate carbon emissions pathways from source sectors to atmospheric accumulation

Communicate complex multi-stage processes to reviewers and non-specialist audiences

Reveal hidden patterns in resource allocation that tables and bar charts cannot show

Types of Sankey Diagrams

How to Create Effective Sankey Diagrams

Applications in Science and Engineering

Ecology: mapping energy flow through trophic levels and nutrient cycling in ecosystems

Chemical engineering: tracking mass and energy balances in reactor systems and refineries

Environmental science: visualizing water usage, carbon footprints, and waste management flows

Healthcare: illustrating patient pathways, treatment outcomes, and hospital resource utilization

Urban planning: analyzing transportation flows, electricity distribution, and city metabolism

Economics: depicting trade flows, supply chains, and national resource consumption patterns

Frequently Asked Questions