At a glance

Draw.io (diagrams.net) PlantUML
Best for Anyone wanting free, full-featured diagramming Software architects who need comprehensive UML diagram support
Starting price Free Free
Free tier
Open source
Free tier available
Open source
Confluence Plugin
Free
IDE integration
Many Shapes
No Account
Open source
Text-based
UML diagrams

Draw.io (diagrams.net)

Strengths

  • Open source and transparent
  • Includes Free as a core feature, purpose-built for diagramming workflows
  • Fully open-source — you can self-host, audit the code, and avoid vendor lock-in
  • The core product is free with no paywalled essentials

Weaknesses

  • May lack some advanced features
  • Self-hosting is free but requires server maintenance and DevOps knowledge
  • Fewer built-in features means you may need additional tools to cover gaps
  • Ecosystem of third-party integrations is smaller than the market leaders in diagramming

PlantUML

Strengths

  • Most comprehensive UML support of any diagramming tool
  • Text-based format integrates with version control
  • Wide IDE support (VS Code, IntelliJ, Eclipse)
  • Active community with 15+ years of development

Weaknesses

  • Steep learning curve for the text syntax
  • Output style is functional but not aesthetically modern
  • Layout control is limited — auto-layout can produce awkward results
  • Less suitable for non-UML diagram types

The bottom line

Pricing: Both Draw.io (diagrams.net) and PlantUML are free, so this decision comes down to features and philosophy rather than budget.

Feature gaps: Draw.io (diagrams.net) offers Confluence Plugin, Free and Many Shapes that PlantUML lacks. PlantUML brings IDE integration, Open source and Text-based that Draw.io (diagrams.net) does not have.

Open source: Both Draw.io (diagrams.net) and PlantUML are open source, so self-hosting and code audits are on the table with either choice.

Where each tool shines: Draw.io (diagrams.net)'s biggest strengths are: open source and transparent. includes free as a core feature, purpose-built for diagramming workflows. PlantUML's biggest strengths are: most comprehensive uml support of any diagramming tool. text-based format integrates with version control.

Watch out for: With Draw.io (diagrams.net), users commonly note that may lack some advanced features. With PlantUML, the main complaint is that steep learning curve for the text syntax.

Choose Draw.io (diagrams.net) if...

  • You need a tool built for anyone wanting free, full-featured diagramming
  • You specifically need Confluence Plugin and Free
  • You care about includes free as a core feature, purpose-built for diagramming workflows

Choose PlantUML if...

  • You need a tool built for software architects who need comprehensive uml diagram support
  • You specifically need IDE integration and Open source
  • You care about text-based format integrates with version control

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