Mermaid vs D2: Modern Diagram Languages for Product Teams
Discover whether Mermaid or D2 is the better diagram-as-code language for your product and platform teams. Compare syntax, collaboration, integrations, and AI tooling.
Mermaid vs D2: Modern Diagram Languages for Product Teams
Mermaid and D2 lead the new generation of diagram-as-code tools. Both aim to make architecture diagrams easy to write, share, and maintain in Git-based workflows. This comparison highlights where each language excels so you can choose the right option for your documentation and collaboration stack.
Why This Comparison Matters
- Product and platform teams need fast, iterative diagramming.
- Both languages integrate seamlessly with UniDiagram for AI-assisted editing.
- Picking the right syntax reduces friction in onboarding and code reviews.
Feature Snapshot
| Capability | Mermaid | D2 |
|---|---|---|
| Release Year | 2014 | 2022 |
| Syntax Style | Markdown-inspired | Indentation-based |
| Auto Layout | Theme-driven | Intelligent defaults |
| Diagram Types | Flowcharts, ERD, Gantt, user journeys | System architecture, cloud maps, ERD |
| Learning Curve | Beginner-friendly | Beginner-friendly |
| Live Preview in UniDiagram | ✅ | ✅ |
Syntax Comparison
Mermaid User Journey Example
journey
title Checkout Experience
section Browse
Customer: 4: Discover product
section Cart
Customer: 3: Add to cart
section Payment
Customer: 2: Complete checkout
D2 Product Architecture Example
web: Next.js Frontend
api: Application API
payments: Payment Provider
web -> api: GraphQL
api -> payments: Secure webhook
Insight: Mermaid offers many out-of-the-box diagram types. D2 focuses on flexible graphs that auto-layout into clean architecture views.
Collaboration Workflows
Mermaid Strengths
- Extensive community snippets and templates for product requirement documents.
- Works directly inside GitHub markdown, Confluence, and Notion.
- Rich ecosystem of plugins for VS Code, JetBrains, and docs frameworks.
D2 Strengths
- Human-readable diffs that keep pull requests tidy.
- Built-in themes (
default,sketch,neutral) adapt to company branding. - Perfect for pairing with infrastructure-as-code reviews due to YAML-like structure.
Performance and Hosting
| Requirement | Mermaid | D2 |
|---|---|---|
| Browser Rendering | ✅ Native support | ✅ via WASM |
| CLI Rendering | ✅ @mermaid-js/mermaid-cli | ✅ Official D2 binary |
| Embedding in Docs Portals | ✅ Markdown & MDX | ✅ Static site integrations |
| Large Diagram Handling | ⚠️ Layout tweaks needed | ✅ Automatic spacing |
FAQs
Which language is faster for prototyping?
Mermaid. You can paste snippets into UniDiagram, tweak colors, and share a live preview within seconds.
Does D2 support the same variety of diagrams as Mermaid?
Not yet. D2 specializes in systems thinking and cloud architecture. Mermaid covers additional chart types like timelines, user journeys, and gantt charts.
Can my team use both languages in UniDiagram?
Absolutely. UniDiagram detects your syntax automatically, offers AI suggestions to improve clarity, and exports branded assets regardless of the language you choose.
Decision Guide
| Team Priority | Recommended Language |
|---|---|
| Product documentation with charts | Mermaid |
| Architecture reviews and runbooks | D2 |
| AI-assisted editing | Both (UniDiagram) |
| Publishing to stakeholder decks | Mermaid |
| Managing infrastructure topology | D2 |
Final Recommendation
If your goal is to publish polished diagrams in product wikis, Mermaid delivers unmatched variety and instant embeds. For teams mapping services, environments, and dependencies, D2 offers clean layouts with minimal syntax. Either way, UniDiagram unifies your workflow—import code, iterate with AI, and export ready-to-share visuals across your organization.