What is a sankey diagram?

A sankey diagram shows how a quantity flows between stages, drawn as nodes connected by links whose width is proportional to the flow's size. It is the chart type for tracing where something comes from and where it goes - customer journeys between pages, budget moving between categories, traffic flowing between sources and outcomes.

Which field is the source, and which is the target?

The first Column field is the source (where each flow starts) and the second is the target (where it ends). Each row in your data becomes one link between one source value and one target value. The optional Row field sets that link's width; without one, every link defaults to the same width, weighted by row count rather than any real quantity.

What happens if a flow points back to the same value it started from?

A self-referencing flow (where source and target are the same value) doesn't disappear or error - it's automatically relabeled so the target node shows as 'Name (Target)', keeping it visually distinct from the source node of the same name. The same relabeling is applied chart-wide, to every target node, the moment the system detects any circular flow anywhere in the dataset (A to B to C back to A) - it's a structural safeguard, not a per-row toggle you control.

Can I highlight a node's full connected path on hover?

Yes. Sankey Styles has a Highlight Connected Path toggle - when on, hovering any node dims everything except that node and every link and node connected to it, making it easy to trace one path through a busy diagram. It's off by default, and automatically disabled on very large diagrams regardless of this setting, to protect performance.

What happens with a very large number of nodes or flows?

Two safeguards apply automatically, and neither one silently discards data without a trace. First, before rendering: only the 50 highest-volume source nodes are kept, each keeps its highest-value individual flows, and every smaller flow from that source is rolled into one synthetic '(Source) Other' link carrying the true summed value of everything excluded - so the total volume from that source still reads correctly even though individual small flows aren't shown one by one. A notice appears whenever this rollup happens. Second, once the diagram still has more than roughly 200 nodes and links combined after that, rendering-time safeguards kick in - reduced layout quality, and dragging and connected-path highlighting are force-disabled. At 20 or more nodes, scroll-to-zoom is also added automatically.

Can I change the diagram's orientation, curve style, or add labels to the links themselves?

Not currently through the formatting panel. The diagram always flows left to right with curved links colored by their source node, and link labels (the value shown directly on a flow line, separate from the hover tooltip) are off. These are fixed, sensible defaults rather than configurable settings at this time.

Sankey Diagram | Edilitics Docs

Trace how a quantity flows from one set of stages to the next, with link width showing proportional volume. Best for funnels, journeys, and budget breakdowns.

A sankey diagram shows how a quantity flows from one set of values to another, drawn as nodes connected by links whose width is proportional to the flow's size. Drop exactly two categorical or date fields into Column - the first is the source, the second the target - and optionally one numeric field into Row to set each link's width. Use it when the question is "where does this come from, and where does it go," not just "how much of it is there."

When to Use

A sankey diagram is built for tracing movement between stages: customer journeys between pages, budget allocated across categories, support tickets routed between teams, traffic split across acquisition channels. The width of each connecting link does the communicating - a thick link is a major pathway, a thin one is a minor one - making it easy to spot where most of a quantity actually flows, not just how much exists in total.

The Row field is optional, but skipping it changes what the link widths mean. Without a Row field, every flow defaults to equal width, weighted by how many rows produced it rather than any real quantity - useful for "how many distinct paths exist" but not for "how much volume moved." Assign a numeric Row field when the actual size of each flow is what matters.

Switch to a different chart when:

You're tracking a single linear drop-off through ordered stages, not flows between two open-ended sets of values - use a Funnel Chart
You need exact flow values in a list, not a visual flow diagram - use Text Table
You're comparing totals across categories, not tracing movement between them - use Horizontal Bar

Scenario	Source (Column 1)	Target (Column 2)	Value (optional Row)
Customer journey between site sections	Landing page	Next page visited	Session count
Budget allocation across departments	Budget category	Department	Amount allocated
Support ticket routing	Intake channel	Resolving team	Ticket count
Traffic flow by acquisition source	Acquisition source	Conversion outcome	Visitor count
Energy or material flow between stages	Input stage	Output stage	Volume

Required Inputs

Field	Type	Count
Dimension (Source, Target)	Categorical or Date	Exactly 2
Measure (Flow width)	Numeric	0 to 1

For step-by-step build instructions, see Build Your First Chart.

Formatting Options

The Format tab unlocks after both Column fields are assigned.

Style

Use the chart title to state what's flowing and between what, since node names alone don't always make the direction obvious.

Control	What it does
Show Chart Title	Shows or hides the title.
Enter Chart Title	Title text. Maximum 50 characters.
Font family	Font applied to the title.
Font size	5 to 30.
Bold / Italic	Weight and style.
Alignment	Left, center, or right within the chart container.

Sankey Styles covers node interaction, sizing, and label styling - the controls available for this chart type are deliberately focused, since most of the diagram's layout is handled automatically.

Control	What it does
Draggable Nodes	Lets viewers manually reposition nodes by dragging. Disabled automatically on very large diagrams regardless of this setting.
Highlight Connected Path	When on, hovering a node dims everything except that node and its full connected path. Off by default, and force-disabled on very large diagrams.
Node Width	5 to 100px. Thickness of each node's rectangle.
Node Gap	0 to 50px. Vertical spacing between nodes in the same column.
Font Family / Color / Font size / Bold / Italic	Styling for the node name labels.
Text Case	Uppercase, lowercase, capitalize, or none.

Several things are not currently configurable through this panel: the diagram's orientation (always left to right), link curve style, link color (always inherited from the source node), and value labels printed directly on the links themselves (always off - the tooltip shows the value on hover instead). These are fixed defaults, not settings hidden somewhere else.

Interactivity

The tooltip appears on hover over a node or a link, with different content for each: hovering a link shows its source, target, and value; hovering a node shows the node's name and its total flow value.

Control	What it does
Show Tooltip	Shows or hides the tooltip entirely.
Header / value text styling	Font, size, and color for the labels and values shown in the tooltip.

Animation controls the nodes' and links' transition when the chart first renders or the data changes. Automatically disabled whenever Draggable Nodes is on, since animating a layout the viewer is actively repositioning would fight their input.

Control	What it does
Enable Animation	Turns the transition animation on or off.
Duration	How long the transition takes.
Delay	How long the transition waits before starting.
Easing Function	The transition curve.

Emphasis controls the visual response when hovering a node or link - a scale-up effect and a drop shadow. Off by default, and distinct from Highlight Connected Path, which dims unrelated elements rather than scaling the hovered one.

Control	What it does
Show Emphasis	Turns hover effects on.
Focus Type	Item, Series, or None.
Enable Scale	Scales the hovered element up slightly.
Scale Size	1.0x to 2.0x.
Shadow Blur / Color / Offset X / Offset Y	Drop shadow styling on the hovered element.
Border Width	Border added around the hovered element.

Enable the Toolbox when viewers need to export the diagram or inspect its underlying data.

Control	What it does
Show Toolbox	Shows or hides the toolbox icon bar.
Save as Image	Adds a download icon that saves the diagram as a PNG.
Data View	Adds an icon that opens the underlying data table in a separate view.

Best Practices

Assign a Row field whenever the actual flow size matters. Without one, every link defaults to equal width weighted only by row count - fine for "how many distinct paths exist," misleading if you're trying to show "how much volume moved." If the question is about real quantity, always assign a measure.

Watch for unexpected "(Target)" labels - they signal a circular flow somewhere in the data. If any path loops back on itself anywhere in the dataset (even one you didn't intend to chart), every target node in the entire diagram gets relabeled to stay distinct from sources of the same name. If this shows up unexpectedly, check your source and target fields for an unintended cycle.

Treat a "(Source) Other" node as a real signal, not noise. When a source has too many small individual flows to show one by one, they're automatically rolled into one "(Source) Other" link carrying their true summed value - so the source's total still reads correctly, but the breakdown behind that bucket isn't visible on the chart. If that breakdown matters, filter the underlying data to a narrower set of sources or targets rather than relying on the chart to show everything.

Keep node count low enough to read without scrolling. Past 20 nodes, scroll-to-zoom kicks in automatically, which keeps the chart usable but means viewers can no longer see the whole flow at once. If the full picture matters, filter the underlying data to the most relevant source or target values first.

Don't rely on link curve, color, or orientation customization - they're fixed. If brand guidelines require a specific curve style or link coloring scheme, that's not adjustable on this chart type today; plan dashboard styling around the existing left-to-right, source-colored default rather than expecting per-chart overrides.

Use Highlight Connected Path for diagrams with more than a handful of crossing flows. Once several nodes share links, tracing a single path by eye gets difficult. Turning this on lets viewers isolate one node's full upstream and downstream flow with a single hover.

FAQs

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Sankey Diagram