D2 vs PlantUML: Choosing the Right Diagram Language for Engineering Teams
Evaluate D2 and PlantUML diagram languages side by side. Understand syntax, collaboration workflows, CI/CD usage, and which tool accelerates engineering documentation.
D2 vs PlantUML: Choosing the Right Diagram Language for Engineering Teams
D2 and PlantUML both let you describe diagrams using plain text, making it easier to version-control architecture ideas and automate documentation. Yet the two languages embrace different philosophies. This guide compares D2's modern developer experience with PlantUML's battle-tested power so you can standardize on the right tool.
Executive Summary
- D2 prioritizes readability, defaults, and AI-assisted layouts.
- PlantUML provides exhaustive control and decades of UML-first features.
- Both languages integrate with UniDiagram, enabling your team to collaborate on diagrams and export production-ready assets.
Headline Differences
| Capability | D2 | PlantUML |
|---|---|---|
| Release Year | 2022 | 2009 |
| Syntax Style | YAML-esque, indentation-friendly | Script-like with UML keywords |
| Auto Layout | AI-assisted with default spacing | Manual tuning via directives |
| Diagram Types | System designs, cloud maps, ERDs | Full UML suite, sequence, deployment |
| Best Team Fit | Product delivery squads | Enterprise architecture groups |
Syntax Comparison
D2 System Diagram
app: Web App
api: API Service
queue: Message Queue
worker: Background Worker
app -> api: REST calls
api -> queue: Publish events
queue -> worker: Consume
PlantUML Component Diagram
@startuml
package "Web App" as App
node "API Service" as API
queue "Message Queue" as MQ
component "Background Worker" as Worker
App --> API : REST calls
API --> MQ : Publish events
MQ --> Worker : Consume
@enduml
Takeaway: D2 uses indentation and natural labels, while PlantUML exposes explicit diagram elements and stereotypes.
Developer Productivity
Why Teams Love D2
- Instant diagrams with minimal configuration thanks to auto layout.
- Markdown-style comments and attribute blocks make it easy to read in pull requests.
- Built-in theming lets you align diagrams with your design system quickly.
Why Teams Stick with PlantUML
- Rich UML semantics (use case, component, deployment) suited for enterprise governance.
- Mature ecosystem of IDE plugins, server renderers, and CI integrations.
- Precise control over lifelines, activation bars, and message arrows in sequence diagrams.
Collaboration and Workflow
| Workflow Need | D2 | PlantUML |
|---|---|---|
| Git reviews | ✅ Friendly diffs | ⚠️ Verbose for complex diagrams |
| Cloud documentation | ✅ Templates for AWS, Azure, GCP | ✅ Extensive icon packs |
| Sharing with non-technical stakeholders | ✅ Clean layouts by default | ✅ Export to PNG/SVG/PDF |
| Legacy UML support | ⚠️ Not native | ✅ First-class |
Performance in CI/CD
- D2 compiles via Go, making it lightweight for containerized pipelines. Combine it with UniDiagram's CLI to render diagrams as part of documentation builds.
- PlantUML leverages Java or WebAssembly runtimes. Use PlantUML Server or Kroki for distributed rendering across microservices.
Automation Recipes
- Docs Preview: Run
d2 --watchlocally and sync with UniDiagram to share review URLs in minutes. - Architecture Governance: Use PlantUML's stereotype enforcement and add UniDiagram's export pipeline to keep diagrams consistent across teams.
FAQs
Which language is easier to adopt?
D2 offers lower friction with human-readable syntax and automated layout. PlantUML requires more setup but rewards teams that need strict UML notation.
Can D2 replace PlantUML for enterprise modeling?
Not entirely. D2 focuses on pragmatic architecture sketches and modern product diagrams. For regulatory documentation or full UML compliance, PlantUML remains the better option. However, UniDiagram lets you manage both formats in a single workspace.
How do I migrate diagrams from PlantUML to D2?
Start by importing your PlantUML files into UniDiagram, export to SVG for stakeholders, and gradually rebuild key diagrams in D2 to take advantage of its simplified syntax.
Recommendation Matrix
| Scenario | Recommended Language |
|---|---|
| Rapid prototyping for product squads | D2 |
| Enterprise UML documentation | PlantUML |
| Multi-cloud architecture reviews | D2 |
| Formal sequence diagrams for QA | PlantUML |
| Collaborative editing with AI assistance | D2 via UniDiagram |
Final Thoughts
Selecting between D2 and PlantUML depends on your audience and documentation lifecycle. D2 speeds up everyday collaboration and keeps diagrams legible in pull requests. PlantUML remains indispensable when you need compliance-ready UML artifacts and precise control.
No matter which syntax you favor, UniDiagram unifies your workflow. Paste your D2 or PlantUML code, enhance it with AI recommendations, and publish shareable diagrams that move projects forward.