TryMermaid

AI Mermaid diagram generator Pro

Describe a diagram in plain words and get Mermaid code that renders, checked by the Mermaid parser before you see it. Flowcharts, sequence diagrams, ER diagrams, Gantt charts and more. Included with TryMermaid Pro.

sequenceDiagram
    actor User
    participant App
    participant Auth as Auth service
    User->>App: Sign in with email
    App->>Auth: Check password
    Auth-->>App: Token
    App-->>User: Dashboard
Loading the tool…

How to do it

  1. Step 1

    Describe it

    Describe the process, system or flow you want to draw.

  2. Step 2

    Pick a type

    Leave the type on Auto or pick flowchart, sequence, ER and so on.

  3. Step 3

    Generate

    The generator writes the Mermaid, checks it, and shows a preview.

  4. Step 4

    Refine it

    Copy the code, or open it in the editor to refine and export it.

From description to diagram

Most of the effort in a diagram is the first draft: picking the boxes, naming them and wiring them up. The generator does that part in seconds, and the editor makes the rest, rewording and rearranging, quick.

Writing a good prompt

Say who the actors are, list the steps in order, and mention branches and failures explicitly: "if the card is declined, show an error and let them retry". Asking for a specific type ("as an ER diagram", "as a Gantt chart starting 1 March") gets you exactly that.

Working from your AI assistant instead

If you already work in Claude, Cursor or VS Code, TryMermaid's MCP server lets the assistant create and save diagrams in your account directly, using your own AI subscription.

What this does not do

  • The model can misunderstand a vague description; name the steps and actors you want to see.
  • Prompts are limited to 2,000 characters, and Pro includes 50 generations a day.
  • Generated diagrams are a first draft: check that they say what you mean before you publish them.

Frequently asked questions

How do I use the AI generator?

Describe what the diagram should show, as you would to a colleague: the steps, who does what, what depends on what. Naming the diagram type helps ("a sequence diagram of…"), but the generator picks one if you do not. It returns Mermaid code and a preview.

Will the code actually render?

Every result is parsed with the same Mermaid parser the editor uses before you see it. If the first attempt does not parse, the error is sent back to the model for one automatic repair, so what you get is valid Mermaid.

Is it free?

The AI generator is part of TryMermaid Pro and includes 50 generations a day. Pro also includes unlimited saved diagrams and the MCP server for Claude, Cursor and other AI agents.

What happens to my prompt?

Your prompt is sent to Anthropic's Claude API to generate the diagram, and it is not used to train models. Prompts are not stored by TryMermaid after the response is returned.

Can I edit the result?

Yes. Open the result in the editor to adjust it in code or, for flowcharts, by dragging shapes on the visual canvas. Or describe the change and generate again.

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