Sankey Diagram vs Network Diagram: Which to Use
A network diagram shows who is connected to whom; a Sankey shows how much moves along each connection in one direction. Compare them and choose the right one for your data.
A network diagram is about structure: what is connected to what. A Sankey is about quantity: how much moves along each connection, from left to right.
The example is 500 support requests that arrive, are handled by Team A or Team B, are sometimes passed on, and end up resolved. As a network it would be a few nodes and lines. As a Sankey, the passes are visible as amounts.
A Sankey wants a direction and a measure. If your data has neither, such as friendships or links between pages, a network diagram is the better tool.
Structure or quantity
A network diagram shows nodes and the links between them, and positions nodes by how connected they are. Link thickness is optional. A Sankey fixes the layout from left to right and makes thickness the point.
What a Sankey needs
Each link needs an amount and a direction, and the layout reads best when there are no long cycles. A flow that returns to an earlier node is drawn as a return flow.
- Network: any connections, no amounts needed.
- Sankey: directed amounts, ordered left to right.
- Network: good for clusters and hubs.
- Sankey: good for volumes, losses and shares.
Choosing
If the question is who is connected to whom, use a network diagram. If it is how much passes between them, use a Sankey.
Key points
- All 500 requests are resolved: 240 by Team A, 230 by Team B and 30 by Team C.
- Team A passes 60 requests to Team B, which receives 260 in total and passes 30 on to Team C.
- Team C only handles requests passed from Team B.
- The figures are invented.
The example’s data
Invented counts, balanced at every node.
| From | To | Amount (requests) |
|---|---|---|
| Requests received | Team A | 300 |
| Requests received | Team B | 200 |
| Team A | Resolved | 240 |
| Team A | Team B | 60 |
| Team B | Resolved | 230 |
| Team B | Team C | 30 |
| Team C | Resolved | 30 |
The same data as CSV
source,target,value
Requests received,Team A,300
Requests received,Team B,200
Team A,Resolved,240
Team A,Team B,60
Team B,Resolved,230
Team B,Team C,30
Team C,Resolved,30How it works
Check that each link has an amount
If connections have no amounts, a network diagram suits better.
Check that each link has a direction
Left to right is clearest.
List the links
From, to and amount.
Check the balance
Each team should pass on what it received plus nothing it did not.
Frequently asked questions
What if my data has cycles?
A flow that closes a loop is drawn as a return flow. Many cycles make a network diagram the clearer choice.
Can a Sankey show hubs?
A node with wide ribbons in and out reads as a hub, but a network diagram shows hubs and clusters better.
Edit this handoff Sankey
Open the example as your own chart and enter your handoff counts.
