UML Diagram Generator
AI UML class, state, and activity diagrams. Describe your diagram in plain English below — free, no account needed. Output stays editable as draw.io XML and can be exported as SVG or PNG after signup.
Export anywhere
Copy the draw.io XML and import it into diagrams.net, draw.io desktop, or Confluence.
Edit visually
Click "Save & Edit Diagram" to open the result in AIDrawIO — drag, restyle, and re-prompt with better models.
Upgrade for more
Free tier: Gemini Flash, 5/hour. Sign up for GPT-5, Claude, unlimited, SVG/PNG export.
See it in action
ExampleUML class diagram for a library system: Book, Author, Member, Loan, Librarian — with methods and relationships.
When to use this tool
Use it when you need UML class, state, or activity diagrams for software design and documentation.
Use it for object-oriented models where entities, methods, and relationships need to be reviewed visually.
Use it when you want a fast UML draft that can still be polished for engineering handoff or documentation.
Example prompts
Prompt 1
UML class diagram for a library system: Book, Author, Member, Loan, Librarian — with methods and relationships.
Prompt 2
UML class diagram for subscription billing with Customer, Subscription, Invoice, Plan, PaymentMethod, and UsageRecord entities.
Prompt 3
Activity diagram for incident response workflow with detect, classify, mitigate, validate, and postmortem branches.
Prompt 4
State diagram for an order lifecycle with draft, pending, paid, fulfilled, refunded, and cancelled states.
Prompt tips that improve results
Name the main actors, services, systems, or tables instead of describing the diagram vaguely.
Include boundaries, traffic direction, failure paths, or data stores when those details matter to the audience.
After generation, use a follow-up prompt to add labels, security controls, or a second level of detail instead of overloading the first prompt.
Good fit for technical docs
AIDrawIO is built around engineer-first diagram workflows. Generate the first version fast, keep the XML editable, and link the output into docs, reviews, runbooks, or design discussions.
Use category pages for broader discovery
If you are still deciding between diagram types, browse the broader AI diagram generator, technical diagram generator, and draw.io AI generator pages linked below.
Related resources
Go deeper with nearby tool pages, prompt libraries, examples, and guides for this diagram workflow.
Related tools
Switch to adjacent generators when you need a different level of detail or diagram style.
Sequence Diagram Generator
Generate sequence diagrams for API calls, OAuth flows, payment flows, and distributed message exchanges.
State Diagram Generator
Model state transitions, events, and actions for any system or UI component.
ERD Generator
Generate ER diagrams with tables, columns, keys, and relationships. Export draw.io XML or SVG.
Prompt libraries and examples
Copy proven prompts and browse concrete diagram patterns close to this workflow.
ERD Prompts
ERD prompts work best when they name the entities, relationships, and key attributes or constraints. These examples help you generate a clean first-pass schema diagram before you finalize table details.
Sequence Diagram Prompts
Sequence diagrams are easiest to generate when the prompt names actors, the order of requests, and any alternate or failure paths. These prompts give you a clean base for auth flows, API interactions, and service-to-service messaging.
OAuth2 Login Flow
Sequence diagram with token exchange, MFA, refresh rotation, and error states
Event-Sourced Order Management
Kafka-based saga with OrderService, InventoryService, PaymentService — failed payment compensation
Guides and category pages
Learn the notation, best practices, and nearby commercial-intent pages around this diagram type.
Mermaid 与 PlantUML：如何选择
Mermaid 与 PlantUML 是最主流的 Diagram-as-Code 方案，适用场景与学习成本各不相同。
系统设计图：该画什么，怎么画
系统设计图将架构思路变成可沟通、可评审、可落地的工程资产。
AI Technical Diagram Generator
AIDrawIO focuses on technical diagrams engineers actually need: architecture diagrams, UML, ERDs, sequence diagrams, infrastructure maps, and cloud designs. Prompt first, then keep refining the result as an editable diagram.
AI Diagram Generator
AIDrawIO turns plain-English prompts into technical diagrams you can keep editing. Describe the system, process, or workflow you want, then export draw.io XML or share the result as SVG or PNG.
Mermaid vs PlantUML vs draw.io
Choose Mermaid for lightweight diagrams in docs, PlantUML for broader diagram-as-code depth, and draw.io for visual editing. Use AIDrawIO when you want AI to generate the first draft before continuing in Mermaid, PlantUML, or draw.io-oriented workflows.
Want this for your team?
AIDrawIO Pro gives your whole team unlimited diagram generation, shared workspaces, version history, and access to GPT-5 and Claude.
See pricingOther diagram generators
Frequently asked questions
Can this generate more than UML class diagrams?
Yes. It can help with class, state, and activity diagrams, depending on the prompt and the structure you ask for.
What makes a UML prompt stronger?
Specify the diagram type, the important entities or states, and the relationships or transitions you want shown.
Is this tool really free?
Yes. You get 5 free generations per hour with no account required. Sign up for unlimited access with GPT-5, Claude, and Gemini Pro.
What diagram formats can I export?
The generated diagram is draw.io XML. Copy it and import it into draw.io or diagrams.net. Sign up to also export as SVG or PNG directly.
Which AI models are used?
The free tier uses Gemini Flash. Subscribers get access to GPT-5, Claude Sonnet, Gemini Pro, and more — with better layout quality.
Can I edit the generated diagram?
Copy the XML and open it in draw.io, or click "Save & Edit Diagram" to open it in AIDrawIO where you can visually edit, restyle, and re-prompt.
How do I get started?
Describe your diagram in the box above, then click Generate (or press ⌘↵). The placeholder text shows you the kind of detail that works best.
Will my prompts be used to train AI?
No. Prompts are sent directly to the AI provider and are not stored or used to train models by AIDrawIO.