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Frequently Asked Questions

Common questions about using SankeyGen, how your data is handled, and what you can do with the diagrams you create.

What is a Sankey diagram used for?

A Sankey diagram shows how a quantity flows from one set of categories to another, with the width of each connection scaled to its value. They're commonly used for budgets and spending, website or app funnels, energy or material flows, and any process where something splits, combines, or moves through stages.

Do I need to create an account?

No. SankeyGen doesn't have accounts, logins, or sign-up forms. Open the site and start building.

Is it actually free?

Yes. The tool is free to use with no usage limits or paywalled features. There's an optional link to support the project if you find it useful, but nothing is gated behind it.

What happens to my data? Is it private?

Your data stays in your browser. The values you enter are sent to a server only to calculate the diagram layout, the math behind where nodes and ribbons are positioned, and nothing else. There's no database, no account, and nothing you enter is stored on a server.

Will I lose my work if I close the tab?

No. SankeyGen automatically saves your work in your browser as you go, so closing the tab or refreshing the page won't lose your progress. It will be there the next time you open the tool in the same browser. You can also clear this saved data any time from the Data panel.

How do I enter my data?

You can either type your data into the table or upload / paste a CSV. Use the Google Sheets template to convert your existing data into a compatible layout, then export it as a CSV and upload it. The template works well with raw data (e.g., 1,000 individual lead records) or summarized data.

Can I control colors, fonts, and labels?

Yes. Choose from several built-in color themes or set your own base color, and change the font from the style panel. Node labels can be renamed directly by double-clicking them on the diagram.

What does Combine columns do?

It controls how nodes with the same name are merged across columns. All merges every matching node into one wherever it appears. Final only merges them in the last column. Off never merges them, even if the names match.

What can I export?

You can export your diagram as a PNG image, a PowerPoint slide, or a swipeable, mobile-ready Instagram carousel that breaks a multi-stage diagram into a series of slides.

Why isn't my diagram showing up?

This is almost always a data formatting issue. Double check that every row has a source, a target, and a positive numeric value, and that stages flow in one consistent direction. Starting from the sample data and swapping in your own values a few rows at a time is a reliable way to spot the row that's causing trouble.

Is there a node limit?

Yes. The data table holds up to 100 rows, and a single path can span up to 10 stages. You'll also see a warning if a diagram grows past around 150 unique nodes, since readability drops off well before you'd hit either limit.

Can I use SankeyGen commercially?

Yes. Diagrams you create and export are yours to use however you like, including in commercial work and client deliverables.

Who built SankeyGen, and why?

I'm David. I build small tools for fun, usually just for myself, and this one started the same way. I liked it enough to keep going and put it out there for anyone else who might find it useful. I appreciate the other Sankey tools out there, but felt there was room to simplify how you get data in and add a few features I found myself wanting. Consider supporting my work if you find it useful.