Flowchart
Last updated: 2026-05-01
A flowchart is a diagram in which boxes represent steps or states and arrows represent the order in which a reader should follow them. Decision points (drawn as diamonds in classic flowcharting and as {Diamond} shapes in Mermaid) split the path along labelled branches.
In Mermaid, a flowchart begins with the keyword flowchart followed by a direction (TD for top-down, LR for left-to-right, etc.). The tool itself decides the layout — you provide nodes and edges, not coordinates.
Flowcharts are easy to over-use. If your diagram is mostly about who sends what message to whom, a sequence diagram is clearer. If it is about how the same thing transitions through states, a state diagram is clearer. Reach for a flowchart when the story is “first this happens, then that, with branches”.
See the dedicated flowchart guide and cheat sheet for syntax details.
Related
- Sequence diagram — A diagram that shows messages exchanged between actors over time, drawn with vertical lifelines and horizontal arrows.
- State diagram — A diagram that shows the discrete states an entity can be in and the events that move it between states.