About
About OnUML
OnUML is a web-based workspace for creating, editing, rendering, and sharing text-defined diagrams.
What OnUML provides
OnUML helps people work with PlantUML and Mermaid through an online editor, live previews, export tools, sharing workflows, and AI-assisted diagram features. The product is designed for software documentation, architecture discussions, technical planning, and other diagram-as-code workflows.
Ownership and operation
OnUML is a product operated by myun L.L.C. The OnUML name identifies the product and publishing brand; myun L.L.C. is the operating organization identified across the site's policies and structured data.
Technical content
The OnUML blog publishes practical diagram guides, syntax examples, workflow comparisons, and troubleshooting material. Our Editorial Policy explains how sources, updates, corrections, and assisted tools are handled.
Contact
Questions about the product, published content, privacy, or corrections can be sent through the contact page.