AI Mermaid diagram generator
Describe a process, system or idea in plain English and get a clean, editable Mermaid diagram in seconds.
Generate any type of diagram
Choose a specialised generator for better results, or describe anything above and let the AI pick the right diagram type.
Map processes, decisions and workflows with nodes, shapes and arrows.
Show how services, users and systems exchange messages over time.
Model object-oriented code: classes, members and relationships (UML).
Describe state machines: states, transitions, choices and nested states.
Design database schemas with entities, keys and crow's-foot relationships.
Plan projects with tasks, durations, dependencies and milestones.
Show proportions of a whole with a simple labelled pie chart.
Brainstorm and organise ideas with an indentation-based mind map.
Show events in chronological order, grouped by period or section.
Visualise Git branches, commits, merges and release tags.
Map user experiences step by step with satisfaction scores.
Plot items on a 2×2 matrix for prioritisation and positioning.
Show how quantities flow between categories with weighted links.
Bar and line charts with categorical or numeric axes.
Trace requirements to the elements that satisfy and verify them (SysML).
Document software architecture using the C4 model (context, containers…).
Lay out system components in a grid you control, with spans and nesting.
Visualise network packets and binary formats bit by bit.
Show work items as cards in columns such as To do, Doing and Done.
Draw cloud and infrastructure diagrams with services, groups and icons.
Compare items across several dimensions on a spider chart.
Show hierarchical data as nested rectangles sized by value.
Why generate Mermaid instead of an image?
AI image generators produce pictures you cannot edit. Mermaid is text: every box, arrow and label stays editable, diffable in Git, and renders natively in GitHub, GitLab, Notion, Obsidian and many docs tools. MermaidViewer gives you the speed of AI with the control of diagrams as code.
Tips for better prompts
- Name the diagram type: “sequence diagram”, “ER diagram”, “Gantt chart”.
- List the actors, entities or phases you care about.
- Mention branches, errors, retries and loops explicitly.
- Ask for styling, e.g. “highlight failure paths in red”.
Read the full AI Mermaid prompting guide.
AI generator FAQ
Is the AI diagram generator free?
Yes. You can generate 5 diagrams per day without an account, 15 per day with a free account, and 300 per day on Pro.
Which diagram types can the AI create?
All Mermaid diagram types, including flowcharts, sequence, class, state, ER, Gantt, mindmap, timeline, journey, C4 and architecture diagrams. Pick a type or let the AI choose the best fit.
Can the AI edit an existing diagram?
Yes. Open your diagram in the editor and press Ctrl/Cmd+K. Choose Edit and describe the change, or choose Fix to repair syntax errors automatically.
Is my prompt stored?
Prompts are sent to our AI provider to generate the diagram and are not used to build a public gallery. We only keep a usage counter to enforce daily limits.
What makes a good prompt?
Name the diagram type, the main actors or steps, and any branches or error cases. For example: “Sequence diagram of a password reset with email token expiry after 15 minutes.”