Interaction Diagrams, Instantly

An interaction diagram maker is a tool for creating sequence diagrams that show how participants — users, services, and systems — exchange messages over time. MakeCharts generates these diagrams automatically from a plain-text description or through a manual step-by-step editor.

A sequence diagram is a UML diagram that maps the order of messages between participants in a process. Use one when you need to document an API flow, explain a system interaction, onboard a new developer, or align a team on how a feature works end-to-end.

Yes. MakeCharts is free to use with no account required. You can build, customize, and download sequence diagrams at no cost. Free AI credits are included so you can generate diagrams from text descriptions right away.

Type a description of your system interaction into the input box — for example, 'User logs in, frontend sends a request to the backend, backend checks the database, and returns an auth token.' The AI generates a complete sequence diagram with participants, arrows, and notes.

The tool supports eight arrow types: solid line, dotted line, solid with arrowhead, dotted with arrowhead, solid with cross, dotted with cross, async solid, and async dotted. These cover every standard UML message type including synchronous calls, async events, and return messages.

Yes. You can add notes positioned left of, right of, or over any participant. Notes are great for highlighting decisions, timing constraints, error conditions, or context that is not obvious from the message flow alone.

Download your diagram as a PNG or SVG file for use in presentations and docs. You can also copy an embed code to add the live diagram to a website, or share a direct link with teammates who can view it instantly in their browser.

Yes. You can add box-style participants to represent systems and services, or stick-figure actors to represent human users and external agents. Both types support the same message and note features.

Yes. Each message has an 'Activate Target' option that draws an activation bar on the receiving participant, showing it is actively processing. You can deactivate it on a later message to indicate when processing ends.

Absolutely. Technical users can configure every arrow type, participant, and note precisely. Non-technical users can describe their process in plain language and let AI handle the diagramming. Both paths produce professional, shareable interaction diagrams.