PlantUML

by Typora Team · v1.0.0 · updated Oct 17, 2026

PlantUML and ditaa code blocks, drawn by PlantUML on your computer (the plantuml command, or Java and plantuml.jar) or by a Kroki server.

Markdown ExtensionDiagramNetworkRuns programsdiagramplantumlpumlumlditaasequenceclassofflinekroki
PlantUML in Typora

Permissions

When you install it, Typora asks you to allow it to:

  • Send and receive data from https://kroki.io.
  • Run plantuml, java as you, outside the sandbox.

Sandboxed pages. Ships HTML views that run in a sandboxed frame and only see what Typora sends them.

What it adds

Code block renderers
```plantuml, ```puml
```ditaa
Settings
Draw with, Command, Java, plantuml.jar, Kroki server

Readme

PlantUML

Draws ```plantuml / ```puml and ```ditaa code blocks with PlantUML. Choose how in Settings ▸ Extensions ▸ PlantUML ▸ Options:

Draw withNeedsOffline
plantuml command (default)plantuml on your PATH, e.g. brew install plantumlYes
Java and plantuml.jarJava 11 or later and plantuml.jar; set the paths of bothYes
Kroki serverA network connection; the source goes to kroki.io or your own KrokiNo

A fence without @startuml (or @startditaa) is wrapped in one. Local diagrams follow the dark appearance (-darkmode). ditaa is drawn as an image: PlantUML only draws it as PNG.

PlantUML stays running between diagrams so only the first one waits for Java to start. It quits after a minute without work, and when you close the window or switch the extension off.

Permissions

  • process: ["plantuml", "java"] — runs plantuml, or java with your plantuml.jar (-Djava.awt.headless=true -jar <jar> -tsvg -pipe …), by name from your PATH or at the full path set in the options. Nothing else. Typora only allows this after you turn on Settings ▸ Extensions ▸ Allow extensions to run programs and accept the permission.
  • network: ["https://kroki.io"] — only with Kroki server: the fence's source is posted to https://kroki.io/plantuml/svg (or /ditaa/svg).