The Sankey diagram maker that does the drawing for you
Most Sankey tools ask for code, a special text syntax, or an hour of dragging bands into place. SankeyCharts.app asks for the numbers. Type each node once, say where it flows and how much, and the diagram sizes every band, lays out the columns, and tells you when the amounts don't add up. Free, in the browser, no account.
Open the Sankey maker: free, no signup
The editor loads with a small budget Sankey. Rename the nodes, change the amounts, and watch the bands resize as you type.
Create Your Sankey Diagram FreeWhat you get, free
The free maker is the whole Sankey editor, not a trial with a watermark clock:
- Bands sized by amount, so a flow twice as large is drawn twice as wide
- Automatic column layout: add a node and the diagram rearranges itself
- A balance check on every node: more out than in, or in than out, is flagged with the difference
- Groups that colour related nodes, and stages that title each column
- Flow labels, and one unit for the whole chart (€, $, GWh, visitors, tonnes …)
- Paste a source, target, value list from Excel, Google Sheets or a CSV export
- Automatic save in your browser: close the tab, come back, it is still there
- Download as a PNG with a free QueryChart account
How it works: one row per node
Under the diagram sits a sheet with one row per node. The Name column is the label on the diagram. Flows to names the node or nodes it feeds, by name or row number; typing a new name adds that node. Flow amount holds one number per flow, separated by commas, and a unit typed with a number ("1500 GWh") becomes the unit of the whole chart.
Every edit redraws the diagram at once. There is nothing to connect by hand and nothing to align: the band widths come from the amounts, and the columns come from where the flows go.
Or paste the data you already have
Most Sankey data already lives in a spreadsheet as three columns: where an amount starts, where it ends, and how much it is. Copy those rows and paste them into the sheet. A header row is recognised and skipped, a unit in the value header ("value (GWh)") becomes the chart's unit, and the same pair listed twice is summed rather than drawn twice. Rows that cannot be drawn, such as a blank name or an amount that is not a number, are skipped and counted, never silently reshaped.
It checks the numbers, too
A Sankey diagram makes a promise: what flows into a node flows out of it, unless the node is a source or an end point. When a node breaks that promise, the editor says by how much ("120 more flows out than in"), so a typo in a budget shows up before anyone reads the chart. A flow with no amount is drawn dashed, and a flow that runs back upstream is drawn as a return line under the diagram instead of tangling the columns.
Start from your own numbers, or from a template
The editor opens with a small household budget so the first thing you see is a working Sankey. Replace it with your own nodes, or open the template rail to start from one of the ready-made Sankey diagrams in QueryChart's library: budgets, cash flow, energy, supply chains, marketing funnels and more, each with its own example data.
When you need more than the free maker
SankeyCharts.app is the free maker: your diagram, saved in your browser. When a Sankey has to be shared, kept in the cloud, commented on by a team or tracked through versions, that is QueryChart, the platform this maker is built on. Signing up moves the diagram you made here into your new account, with its unit, groups and stages intact.
Frequently asked questions
Is the Sankey diagram maker really free?
Yes. Building Sankey diagrams is free with no account and no time limit. Your work is saved in your browser as you go. Downloading the diagram as a PNG needs a free QueryChart account.
Do I need to know how to code?
No. There is no Python, no JavaScript and no special syntax. You type node names and amounts into a sheet, or paste them from Excel, and the diagram draws itself.
What data does a Sankey diagram need?
Three things per flow: where it starts, where it ends, and how much it carries. That is the source, target, value list most spreadsheets and Sankey tools already use, and it pastes straight into the editor.
Can I use any unit?
Yes, one unit per chart: a currency (€, $, £ and others, printed the reader's way) or any word such as GWh, tonnes or visitors. One unit keeps band widths comparable, which is what makes a Sankey honest.
What happens if my numbers don't add up?
The editor flags the node and says by how much the inflow and outflow differ. It still draws the diagram, so you can see where the gap is and fix the amount.
Can I start from an example?
Yes. The template rail opens QueryChart's Sankey library inside the editor: budgets, cash flow, energy, funnels and more. Pick one and edit its numbers.
Ready to draw your first flow?
The editor opens with a starter Sankey diagram. Type your own nodes and amounts, and the diagram rebuilds itself as you type. No signup required to get started.
Create Your Sankey Diagram Free