draw.io vs PlantUML

draw.io is a free, open-source diagramming tool for creating visual layouts, from flow charts and mind maps to network, architecture, UML, BPMN and floor-plan diagrams. It supports real-time collaboration, and files can be opened and edited across platforms. Users can choose their own storage or save locally with the desktop app; draw.io says it cannot access users' data. No sign-up or credit card is required to start diagramming, and the desktop app is free forever. Diagrams can remain editable or be exported to SVG, PNG or PDF. Supported imports include draw.io, XML, Gliffy, VSDX, Lucidchart, PNG, SVG and JPEG. Integrations include Google, Microsoft, Atlassian, GitHub, VS Code, Notion and Chrome. Interactive diagrams can be embedded in documents, wikis or applications. The listed platforms are web, Windows, macOS, Linux, iOS and Android. Support is available through GitHub Discussions and Stack Overflow. The site says there is no Enterprise tier for SSO.

PlantUML turns textual descriptions into diagrams, covering UML forms such as sequence, use-case, class, object, activity, component, deployment, state, and timing diagrams. It also supports JSON, YAML, EBNF, regex, network, wireframe, Archimate, Gantt, mind map, and WBS diagrams. Outputs include PNG, SVG, LaTeX, EPS, and other listed formats; sequence diagrams can also be rendered as ASCII art. Its browser editor renders diagrams with JavaScript and refreshes them as the text changes. Layout options include Graphviz, Smetana, VizJs, and ELK, though ELK lacks some features. PlantUML offers integrations for tools including GitHub, GitLab, Confluence, WordPress, Slack, Visual Studio Code, Eclipse, and IntelliJ IDEA. It is free, with a plan listed at free, and runs on web, Windows, macOS, Linux, API, extension, and self-hosted platforms. Local installation requires Java, with version 11 or later recommended; Graphviz is needed for some diagrams. PlantUML can also run as a local server, which the project recommends for sensitive diagrams.