PlantUML
PlantUML turns textual descriptions into diagrams, covering UML types such as sequence, use-case, class, object, activity, component, deployment, state, and …
What PlantUML is
PlantUML turns textual descriptions into diagrams, covering UML types 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 sequence-diagram ASCII art. A browser editor uses JavaScript rendering and updates diagrams as code changes. Users can choose among Graphviz, Smetana, VizJs, and ELK layout engines; ELK supports orthogonal layouts but not every feature. PlantUML lists integrations with GitHub, GitLab, Confluence, WordPress, Slack, Visual Studio Code, Eclipse, and IntelliJ IDEA. The software can be installed locally or run as a local server, with Java required and Graphviz needed for some diagrams. The project recommends local hosting for sensitive diagrams. PlantUML is free, though features may vary by license. It generates drawings rather than enforcing consistency in a model.
Good
- Supports a wide range of UML and non-UML diagrams.
- Browser editor updates diagrams as code changes.
- Offers several layout engines.
- Can be run as a local server.
- Integrates with tools including GitHub and Visual Studio Code.
Watch out
- Local installation requires Java.
- Graphviz is needed for some diagrams.
- ELK does not support every feature.
- Does not prevent inconsistent diagrams.
Who it suits
PlantUML suits people who want to produce diagrams from text, including users working with UML and other structured diagram types. Local hosting is an option for sensitive diagrams, while the browser editor supports editing in a browser.
Verdict
PlantUML is a free text-to-diagram tool with broad diagram coverage and multiple output formats. Users should account for its Java requirement locally and its role as a drawing generator rather than a consistency-checking modeling tool.
Plans and prices
From PlantUML's own pricing page, checked 7 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| PlantUML | Free | Open source · Free of charge · Available under several licenses, with some features varying by license |
The facts
Each one read from PlantUML's own pages, with the date it was checked.
Where it runs
- Browser editor
- The site’s editor runs in the browser using a JavaScript rendering engine and updates diagrams as code is edited.checked 7 Oct 2026
- Browser extension
- The official browser extension renders PlantUML diagrams directly inside GitHub without a server, and the site says it uses no tokens or tracking and requests no permissions except clipboard.checked 7 Oct 2026
What it does
- Diagram size
- The FAQ states that image width and height are limited to 4096 by default, with an environment variable or command-line option to change the limit.checked 7 Oct 2026
- Diagram types
- It supports UML diagrams including sequence, use case, class, object, activity, component, deployment, state, and timing diagrams.checked 7 Oct 2026
- Integrations
- The project lists integrations with tools including GitHub, GitLab, Confluence, WordPress, Slack, Visual Studio Code, Eclipse, and IntelliJ IDEA.checked 7 Oct 2026
- Layout engines
- Available layout engines include Graphviz, Smetana, VizJs, and ELK; ELK supports orthogonal layout and does not cover all features.checked 7 Oct 2026
- Local requirements
- Local installation requires Java, with Java 11 or later recommended; Graphviz is needed only for some diagrams.checked 7 Oct 2026
- Notable limitation
- PlantUML functions as a drawing generator rather than a modeling tool and does not prevent inconsistent diagrams.checked 7 Oct 2026
- Other diagrams
- Supported non-UML diagrams include JSON, YAML, EBNF, regex, network, wireframe, Archimate, Gantt, mind map, and WBS diagrams.checked 7 Oct 2026
- Outputs
- Diagram output formats include PNG, SVG, LaTeX, EPS, and ASCII art for sequence diagrams.checked 7 Oct 2026
- Purpose
- PlantUML creates diagrams from simple textual descriptions.checked 7 Oct 2026
- Security profiles
- PlantUML provides security profiles that control access to local files and URLs, including INTERNET, ALLOWLIST, and SANDBOX modes.checked 7 Oct 2026
- Self hosting
- PlantUML can run as a local server, and the project recommends this for generating diagrams that contain sensitive information.checked 7 Oct 2026
- Server privacy
- The FAQ says PlantUML Server does not store diagrams, but warns that traffic goes through HTTP and can be intercepted.checked 7 Oct 2026
- Support
- The project directs users to its community forum for advice and solutions to common layout issues.checked 7 Oct 2026
The company
- Founded
- 2009checked 28 Sep 2026
Money
- Free plan
- Yeschecked 20 Sep 2026
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