Using Mermaid AI

Mermaid AI generates diagrams from natural language prompts in real time. You can describe what you want in plain English, upload files for context, or iterate on an existing diagram by chatting with it. For the full guide, see our Mermaid AI documentation.

How to access Mermaid AI

There are two ways to start using Mermaid AI:

• From the dashboard: Click New diagram. A dialog appears asking "What do you want to diagram?" Select Generate (selected by default), type your prompt, and press enter.
• From inside an existing diagram: Click the Use AI button at the bottom center of the editor. This opens the Mermaid AI chat where you can refine the current diagram using natural language prompts.

Other ways to start a new diagram

When you click New diagram from the dashboard, the "What do you want to diagram?" dialog gives you four options:

• Generate — Mermaid AI builds a diagram from your prompt (default)
• Paste Mermaid code — paste existing Mermaid syntax to render it
• Templates & Diagram types — browse pre-built templates and diagram types
• Start with a blank canvas — open an empty editor

The in-product AI guided tour

The first time you open a diagram, Mermaid runs a short series of one-time, dismissible tooltips that walk you through the AI features — AI Repair, Quick Edit, Use AI, and the Node Toolbar. Click Next to step through, or dismiss at any time. You can revisit the tour later from the help menu.

Uploading files to Mermaid AI

To use a file as context, you have four options:

• Click the plus (+) button in the chat input to select a file
• Drag and drop the file into the chat
• Paste an image or screen capture directly from your clipboard into the prompt box
• Type @ in the prompt box to mention and attach a specific file or asset

Once uploaded, ask Mermaid AI to create a diagram from it.

There is no file size or character limit for AI input.

PowerPoint files: Direct PowerPoint upload isn't currently supported. Export your slides as an image (PNG or JPEG) and upload that image to Mermaid AI instead.

Tips for better results

• Be clear in your prompts. Specific instructions produce better results than vague ones.
• Provide context. Include relevant details like roles, steps, or constraints. Instead of "make a flowchart for user login," try "create a flowchart for user login that includes password reset and email verification steps."
• Iterate. Mermaid AI retains the full conversation context, so you can refine the same diagram with follow-up instructions without starting over. Chat history persists until you manually clear it.

When Mermaid AI asks for clarification

If your prompt could be interpreted more than one way, Mermaid AI may follow up with a Quick question card before generating anything. The card presents a short list of likely interpretations — for example, whether you want to edit existing nodes, change the diagram type, or start over — plus an "I'll specify this myself" option you can pick if none of them fit.

You have three ways to respond:

• Pick an option and click Continue — Mermaid AI uses that as the spec and generates the diagram.
• Choose "I'll specify this myself" — a follow-up prompt field opens so you can describe what you want in your own words.
• Click Skip — Mermaid AI proceeds with its best guess from your original prompt, without waiting for an answer.

Skip is the fastest path when you'd rather see something on the canvas and refine from there. Picking an option (or specifying yourself) usually produces a closer first draft, especially when you already have a clear structure in mind, and tends to use fewer follow-up turns.

What Mermaid AI can do

• Generate diagrams from text prompts in real time
• Convert uploaded files into diagrams — supports 50+ file types including PDFs, transcripts, presentations, Word documents, CSV files, and Mermaid (.mmd) files
• Convert handwritten notes, screenshots, or photos of diagrams into editable Mermaid diagrams
• Refine and expand existing diagrams through conversation

Voice diagramming

You can build and edit diagrams by speaking instead of typing. Voice diagramming uses Mermaid AI under the hood, so the same context, chat history, and AI credits apply — only the input method changes.

To start, click Use Voice at the bottom-left of the editor and describe what you want. Mermaid AI generates and updates the diagram in real time as you speak. You can keep going naturally — ask for follow-up changes, group nodes, convert to a different diagram type, or refine layout — without switching contexts:

• "Create a flowchart for user login with password validation and error handling."
• "Add two-factor authentication after the password step."
• "Group the authentication steps into a separate section."
• "Convert this into a sequence diagram showing how the user, system, and authentication service interact."

Voice diagramming is especially useful when you're thinking through a flow out loud — for example, walking a client through a system in a meeting and adjusting on the fly without breaking the conversation.

The full conversation is saved in the AI chat, so you can iterate further by voice or text, scroll back through previous turns, and restore earlier versions of the diagram from Timeline in the editor toolbar.

You can also jump straight into voice diagramming when you create a new diagram. From your dashboard, click New diagram, and you'll see a voice option in the "What do you want to diagram?" dialog. Select it to start describing your diagram out loud right away — no need to type a prompt or open a blank canvas first. This is handy when you'd rather think out loud than type.

Quick Edit (vibe diagramming)

Quick Edit lets you change a diagram by selecting part of it and describing what you want in plain English, without leaving the canvas or learning Mermaid syntax. It's the same idea you may have seen as vibe diagramming on our blog — describe a change, see it applied, accept or reject.

There are two ways to use it:

From the visual editor:

1. Click a node or edge to select it. (You can also select multiple nodes with Shift-click or marquee drag.)
2. In the floating toolbar, click Quick Edit (the Quick Edit icon).
3. An inline prompt opens. Describe what you want — for example, "Change the color to blue", "Add a step before this one called 'Validate input'", or "Make this edge dashed".
4. Press Enter. Mermaid AI generates the change and shows a diff with the affected lines highlighted.
5. Click Accept to apply the change, Reject to discard it, or use the follow-up field to refine your request before accepting.

From the code editor:

1. Select one or more lines of Mermaid code (or place your cursor on a line).
2. Right-click and choose Edit selected code with AI.
3. An inline prompt opens above the selection. Describe the change you want.
4. Press Enter. Quick Edit returns updated code with diff highlighting.
5. Accept, reject, or follow up.

Quick Edit works on flowchart, sequence, ER, and requirement diagrams. Support for additional diagram types is rolling out — if your diagram type doesn't show a Quick Edit option, the AI chat panel works the same way for whole-diagram edits.

Credits: Quick Edit uses Mermaid AI credits — one credit per accepted change. Rejected suggestions don't deduct credits. See AI credits below for plan limits.

Tips:

• Smaller, specific prompts work better than broad ones. "Add a retry step after the API call" beats "improve this diagram".
• Use the follow-up field to iterate without starting over. The conversation context carries across follow-ups.
• If you're partway through manual edits, accept or reject pending Quick Edit changes before continuing — applying a Quick Edit on top of unsaved edits can produce unexpected merges.

Common use cases

• Converting transcripts into flowcharts — paste a transcript directly into the prompt field, or upload it as a file. Works for meeting notes, lecture transcripts, podcasts, or video captions.
• Turning handwritten notes into diagrams — upload a photo of whiteboard notes or a hand-drawn sketch, and Mermaid AI will replicate the structure, branches, and labels.
• Process documentation — describe a business workflow, role structure, manufacturing process, or project plan in plain language.
• Importing diagrams from other tools — upload a screenshot or photo of a diagram from Miro, Lucidchart, Visio, Excalidraw, whiteboards, or any other diagramming tool. Prompt Mermaid AI to "replicate this diagram" and it will preserve the data, connections, shapes, colors, and structure as an editable Mermaid diagram.

Chat controls

After a diagram is generated, the Mermaid AI interface gives you:

• Clear current chat — start a new conversation
• Create new AI diagram — opens in a new tab
• Full screen — view the diagram full screen
• Pan & zoom — navigate the diagram in chat
• Export — download as PNG or SVG
• Edit — open the diagram in the Mermaid editor
• Save as new diagram (ellipses menu) — save a copy to your dashboard in a new tab
• More details toggle — show or hide the diagram explanation and Mermaid code

AI credits

Each plan includes a different amount of AI credits:

• Basic — 15 AI credits
• Plus — 300 AI credits per year
• Premium — 2,000 AI credits per year
• Enterprise — unlimited AI usage

AI credits reset annually when your subscription renews.

My AI credits are being deducted unexpectedly

AI credits are consumed by several actions, not just the AI chat itself:

• AI chat
• AI Repair (for fixing diagram syntax errors)
• Voice diagramming
• Diagram name updates in some cases

If you believe credits are being deducted incorrectly, please share the steps you were taking when you noticed the deduction so the team can investigate. Visit our Contact Us page with these details.