Diagramming AI - 2026 Pricing, Features, Reviews & Alternatives

Diagramming AI is a cloud-based, AI-powered diagram generation and editing platform that enables software engineers, business analysts, project managers, technical writers, and product managers to create UML diagrams, flowcharts, sequence diagrams, ER diagrams, Gantt charts, mind maps, C4 diagrams, state diagrams, and more. Diagrams can be generated from natural language text prompts, images, or URLs, and are rendered across four supported diagram languages: Mermaid, PlantUML, Graphviz, and D2. A free tier provides access to core editors and Quick Edit functionality, while Starter and Pro paid plans unlock additional AI models and URL-based diagram generation.

The platform combines code-based and visual editing workflows. The V-Edit feature converts text-based diagrams into interactive Excalidraw canvases, allowing drag-and-drop repositioning and visual adjustments without modifying the underlying diagram code. Quick Edit supports element-level size and style changes. An AI chat interface provides iterative suggestions and issue detection throughout the editing process. Format Input optimization refines prompts before generation, and output quantity control (Low, Medium, High) governs the volume of generated results. Over 10 color themes are available for Mermaid diagrams and 40-plus for PlantUML, with template switching supported across diagram languages.

Diagramming AI organizes work through project-based diagram storage with notes, undo/redo support, and version management in a single workspace. Diagrams are shareable via read-only public links through Kroki integration, requiring no recipient login. Export options include SVG and PNG formats for use in presentations, reports, and technical documentation. Multiple AI models are accessible depending on plan tier, including options from the GPT, Gemini, and Claude model families.