How to make a flowchart, step by step

A flowchart shows how a process moves from start to finish. Done well, it makes a confusing process obvious in one glance. Here is how to build a clear one.

The four symbols you need

Oval (terminator): where the process starts and ends.
Rectangle (process): an action or step, such as "Validate the form".
Diamond (decision): a question with two or more exits, usually yes and no.
Arrow (flow line): the direction from one step to the next.

These four cover almost every flowchart. Add other symbols only when your audience already knows them.

Step by step

Define the process and its boundaries: where does it start, and what counts as done?
List the steps in order, as short verb phrases.
Mark every point where the path can split and write it as a question.
Draw the start oval, then place each step below or to the right of the previous one.
Connect everything with arrows, and label the exits of each decision.
Check that every path reaches an end. Loose ends are the most common flaw.
Show it to someone who does not know the process and see if they can follow it unaided.

Common mistakes

Too much detail in one chart: split big processes into a main chart and sub-flows.
Decisions without labelled exits, or with a single exit.
Arrows that cross each other. Rearrange the shapes until they do not.
Mixing directions. Pick top to bottom or left to right and keep it.
Vague steps such as "Handle it". Say what is actually done.

Draw one online

In ExcaliClaw the shapes you need are right there: rectangles, ellipses, diamonds and arrows, in a hand-drawn style that keeps a sketch feeling like a sketch. You can start in the free whiteboard without an account, and sign up when you want the drawing saved.

If you prefer to describe it instead of drawing it, connect an AI assistant over MCP and ask it for a flowchart. The create_flow_diagram tool takes the steps and the connections, with box, ellipse and diamond shapes and labelled edges, and the server lays everything out without overlaps.