Generate, edit, preview, and export diagrams in four modes within one AI-powered workspace Workflow Videos Create Diagrams From Text Or Images Explore four example workflows. OnUML supports text and image inputs, editable diagrams, mind maps, and one-click AI repair when diagram code breaks. Draw.io diagrams with AI Create flexible Draw.io diagrams from text, images, and other source materials with AI. OnUML turns your ideas into editable diagrams with rich built-in shapes, so you can drag, drop, connect, resize, and refine everything directly on the page. PlantUML and Mermaid diagrams Generate PlantUML and Mermaid diagrams quickly with AI, then refine them through prompts or code. OnUML renders changes in real time, so you can keep the diagram, source code, and AI editing flow together. Professional mind maps Unlike the mind map syntax inside PlantUML or Mermaid, OnUML supports a professional mind map diagram type built for structured thinking. Create and refine mind maps with AI, then add, move, and edit nodes directly on the page without switching back to code. AI diagram code repair When PlantUML or Mermaid code has syntax errors, paste it into the code editor and repair it with one click. OnUML helps fix broken diagram code quickly so you can render and continue editing without manual debugging. Choose The Right Mode For Your Diagram OnUML brings Mermaid, PlantUML, Draw.io, and Mind Map workflows into one AI-powered workspace. Choose the mode that matches your work. Mermaid fits quick documentation, PlantUML handles formal UML and technical modeling, Draw.io provides a freeform visual canvas, and Mind Map organizes plans and ideas into editable branches. A lightweight text DSL with markdown-style syntax for fast documentation-driven diagrams. Characteristics A lightweight text DSL with markdown-style syntax for fast documentation-driven diagrams. The biggest strength of Mermaid is simplicity. It is lightweight, the easiest to learn, visually modern, and especially effective when you want diagrams to live directly inside Markdown content. Supported diagram types An engineering-oriented text DSL for formal UML and complex architecture modeling. Characteristics An engineering-oriented text DSL for formal UML and complex architecture modeling. Compared with Mermaid, PlantUML supports a wider range of complex and formal diagram types. The tradeoff is that the code is usually more detailed and more complex to write. Supported diagram types A visual drag-and-drop editor for freeform diagrams, presentation visuals, and whiteboard-style layouts. Characteristics A visual drag-and-drop editor for freeform diagrams, presentation visuals, and whiteboard-style layouts. Compared with Mermaid and PlantUML, Draw.io stands out for direct drag-and-drop editing in the UI. It offers the highest layout freedom across many diagram styles and requires no coding at all. Supported diagram types Architecture Diagram

Network Diagram Whiteboard Layout A visual, node-based mode for brainstorming, planning, learning, and organizing hierarchical ideas. Characteristics A visual, node-based mode for brainstorming, planning, learning, and organizing hierarchical ideas. Generate a structured map with AI, then add, move, and edit nodes directly without maintaining diagram syntax. Supported diagram types Meeting Summary Core Features Of The AI Diagram Generator Create and refine Mermaid, PlantUML, Draw.io, and Mind Map diagrams with AI generation, visual or code editing, live preview, history, export, and sharing Project plans and AI credits Pro increases account capacity for projects, workspaces, and image upload. Credits stay separate as an AI usage add-on. Core editor access with fair-use limits for personal work. Unlock image upload, expanded project capacity, and workspaces with a monthly subscription. Unlock image upload, expanded project capacity, and workspaces with a monthly subscription. AI usage add-on credits Buy credits for extra AI generation, image understanding, premium model runs, and fixed-cost Repair. Credits do not unlock diagrams, project, workspace. Credits expire 6 months after they are issued. Create And Deliver Diagrams In Three Steps Choose the right mode first, describe what you need, then refine and export or share the final result Pick the mode that fits your workflow: Mermaid for quick docs, PlantUML for formal UML, Draw.io for freeform visual diagrams, or Mind Map for structured ideas Use a prompt, rough structure, or template to generate a first draft faster and avoid starting from scratch Refine the diagram, check the rendered result in real time, then export PNG or SVG files or share the finished diagram with a link Frequently Asked Questions Quickly learn about OnUML's core capabilities, how it works, and pricing OnUML is an AI diagram generator and online UML editor that brings Mermaid, PlantUML, Draw.io, and Mind Map workflows into one workspace. It supports natural-language generation, code or visual editing, live preview, repair, history, export, and sharing. OnUML has reasonable usage limits to keep the service stable and the overall experience consistent. For most regular users, day-to-day use will not be affected. OnUML supports four modes: Mermaid, PlantUML, Draw.io, and Mind Map. You can create, edit, preview, and switch between them in one workspace. You can export diagrams as PNG, SVG, and other formats. If you create an account, you can also save diagrams by project for easier access, management, and continued editing later. Mermaid is best for lightweight diagrams in documentation, PlantUML for formal UML and technical modeling, Draw.io for freeform visual layouts, and Mind Map for brainstorming and hierarchical planning. OnUML offers a Free plan with usage and project limits. Pro increases project and workspace capacity, while AI credits cover additional and premium AI usage. See Pricing for current limits and prices.