PlantUML authoring, preview, code navigation, and export in one tool.

UMLMark helps teams keep diagrams and source code aligned by turning PlantUML files into an interactive development surface: write code, generate PlantUML, preview instantly, navigate back to real source files, and export production-ready artifacts.

Why UMLMark

Most diagram workflows break in at least one place:

Diagram preview is disconnected from source code changes.
Navigation from diagram elements back to real code is slow or brittle.
Exporting shareable artifacts is repetitive and error-prone.

UMLMark addresses these problems directly:

Fast PlantUML preview with practical zoom and pan controls.
Source-code navigation from diagram hyperlinks inside VS Code.
One-tool export flow for workspace, document, and current diagram.
Flexible rendering via Local or PlantUML Server modes.

Key Capabilities

Open PlantUML preview with Alt+D (Option+D on macOS).
Auto-update preview while editing.
Zoom and pan controls for large diagrams.
Source-code navigation using UML class or sequence diagrams
Export commands:
- umlmark.exportCurrent
- umlmark.exportDocument
URL utilities:
- umlmark.URLCurrent
- umlmark.URLDocument

Supported File Types

*.wsd, *.pu, *.puml, *.plantuml, *.iuml

Preview interaction (zoom, pan, control bar actions):

Animated demo of UMLMark preview zoom and pan controls

Code navigation from PlantUML hyperlinks:

Class diagram navigation:
Sequence diagram navigation:

Install

From VS Code Marketplace

Open Extensions in VS Code.
Search for UMLMark.
Install the extension published by petercai.

Direct link:

https://marketplace.visualstudio.com/items?itemName=petercai.umlmark

CLI Install

code --install-extension petercai.umlmark

Quick Start

Open a .puml (or other supported PlantUML) file.
Press Alt+D (Option+D on macOS) to open preview.
Edit diagram code and observe live updates.
Use embedded hyperlinks to jump between diagram and source code.
Export outputs from command palette via: umlmark.exportCurrent, umlmark.exportDocument.

Developer Flow (UMLMark Suite)

Recommended end-to-end workflow for Design as Code / Architecture as Code:

Write or update source code.
Generate PlantUML diagrams from source using UML Gen (CLI).
Open generated .puml diagrams in UMLMark preview.
Navigate from diagram elements back to source files.
Iterate: update source, regenerate diagrams, and re-verify in preview.

Flow summary:

source code -> uml-gen generation -> .puml preview in UMLMark -> code navigation back -> iterate

Rendering Modes

UMLMark supports two rendering modes:

Local (default)
PlantUMLServer

Local Render Requirements

Java runtime
Graphviz

Quick install on macOS:

brew install --cask temurin
brew install graphviz

PlantUMLServer Render

Use this mode when you want faster export/preview throughput and have a PlantUML server available.

Example settings:

"umlmark.server": "http://localhost:8080",
"umlmark.render": "PlantUMLServer"

Note: for large diagrams with includes, server POST support is recommended to avoid 414 URI Too Long errors.

Configuration Highlights

Commonly used settings:

umlmark.render
umlmark.server
umlmark.previewAutoUpdate
umlmark.diagramsRoot
umlmark.exportOutDir
umlmark.exportFormat
umlmark.includepaths

Typical project layout:

"umlmark.diagramsRoot": "uml/plantuml",
"umlmark.exportOutDir": "uml"

Ecosystem: UMLMark Suite

Together, these tools support a full code-to-architecture workflow:

Tool	Role
UML Gen (CLI)	Generate class and sequence diagrams from source code
UMLMark (VS Code Extension)	Interactive PlantUML preview, code navigation, export
UMLMark (Eclipse Plugin)	UML generation and usage inside Eclipse

License

This project follows a dual-license model across the UMLMark Suite.

Free for Non-Commercial Use: LICENSE.txt
Commercial Use Requires License: COMMERCIAL_LICENSE.txt

If you need commercial usage guidance for your deployment scenario, contact the maintainer.

Support

If UMLMark helps your team, support the project here:

Support me: https://paypal.me/petercaica

For Contributors

Useful local commands:

# install dependencies
npm install

# compile code
./node_modules/.bin/tsc -p .
# OR use the package.json script
npm run compile

# Package the extension
npx @vscode/vsce package

# Install the .vsix file
code --install-extension umlmark-1.0.8.vsix

Issue tracker: