ChatPlot
AI sequence diagram generator

AI sequence diagram generator: describe the exchange, get the diagram

Describe who talks to whom and in what order, and ChatPlot draws the participants, the messages and the replies. Ask for changes the same way: add a timeout, show the failure case, rename a service.

Try this prompt in ChatPlot Browse templates

Opening the app spends nothing. Your first 5 AI actions are free as a guest, no account needed.

Published

You wrote

A sequence diagram for resetting a password: the user asks for a reset, the web app tells the auth service to send an email, the user opens the link, chooses a new password, and the app confirms the change.
Sequence generated by ChatPlot from the description above: Password reset.
Rendered by ChatPlot from the text above: password reset. No manual drawing.
Refine by chatting

Then add the case you forgot

One follow-up request added the expired-link branch as an alternative block. The original stays in history.

Follow-up request

Show what happens when the reset link has expired: the app says so and offers to send a new one.

One AI action. The previous version stays in history, so you can undo, compare or restore it at any time.

The same sequence diagram after the follow-up request: Password reset with the requested change.
The result of the request on the left, rendered by ChatPlot.

What you can ask for

  • Add or rename participants ("add a cache between the API and the database")
  • Insert, reorder or remove messages and replies
  • Add alternatives and error paths ("show what happens when the token is invalid")
  • Add loops and optional steps ("retry up to three times")
  • Add notes over a participant ("note that the access token expires after 15 minutes")
  • Number the messages, or switch numbering off

When a sequence diagram is the right format

  • Requests and responses between systems: sign-in flows, payments, webhooks, background jobs.
  • Order and timing matter, and the reader needs to see what happens before what.
  • You are reviewing an integration with another team and want the message names to be explicit.

When it is not

  • The process has many decisions but few actors. A flowchart shows branches more clearly.
  • You want an overview of components rather than one interaction. An architecture or block diagram is the better fit.
  • More than roughly eight participants: split the diagram per use case; lifelines get too dense to read.

Limits to know before you start

  • Participants are laid out left to right in the order they appear; you cannot drag lifelines.
  • Very long message labels widen the diagram. Keep messages short and put payload details in the chat or a note.
  • Guest and Free exports carry a small chatplot.io mark; Pro removes it and allows PNG up to 3× resolution. There is no PDF export.
  • AI edits use actions from your plan; theme changes, exports and share links never do.
Plans

Free to try, no account needed

  • Guest: 5 AI actions to try it, up to 3 diagrams saved in this browser, PNG and SVG export with a small chatplot.io mark.
  • Free account (Google sign-in): 10 AI actions every month, unlimited diagrams synced to your account, exports with the mark.
  • Pro: $15 per month or $144 per year, 500 AI actions a month, exports without the mark, PNG up to 3× resolution.

One AI action = one create or edit request that produces a diagram. Failed requests are not charged; templates, history, direction and theme changes, exports and share links never use actions. Team and Enterprise plans are not available. Full pricing.

API authentication sequence diagram Client, API and identity provider exchanging tokens.

All templates

Guides that go deeper

Questions before you start

Does it understand technical terms like OAuth, JWT or webhook?
Usually, yes. The example on this page was written with "auth service" and "token" and came out right. When a term is ambiguous, name the participants explicitly in your first message.
Flowchart or sequence diagram: which should I use?
If the question is "what happens next?", use a flowchart. If it is "who sends what to whom?", use a sequence diagram. The guide flowchart vs sequence diagram shows the same checkout drawn both ways.
Can I start from an example?
Yes. The API authentication sequence template opens in the app without using an AI action.

Try it on a process you keep explaining

Paste the description, get the sequence diagram, then ask for the changes you would ask a colleague for.

Start with this example Open ChatPlot