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MERMAID DIAGRAM GUIDE

Mermaid block diagram online editor

Arrange system blocks and connections to explain structure at a glance. Create the diagram in Mermaid Studio, preview it instantly, and export it when it is ready to share.

Open the Block editor See an example

WHAT IT IS FOR

Make the important relationships clear

Arrange conceptual blocks and connections to explain a system structure without exposing every implementation detail.

  • Sketch system architecture
  • Explain a product boundary
  • Align stakeholders on major components
Why use Mermaid Studio?
  • Write the source as versionable Mermaid code.
  • Preview changes immediately in the browser.
  • Export the finished diagram as SVG or PNG.
  • Start from a related template when you need a head start.

MERMAID EXAMPLE

Start with a working example

Copy the structure, replace the labels with your own domain, and continue in the full editor.

block
  columns 3
  Web["Web"] API["API"] DB[("Database")]
  Web --> API
  API --> DB

HOW TO START

Create your diagram in four steps

  1. 1Choose the blocks that matter to the audience.
  2. 2Group related blocks by boundary or responsibility.
  3. 3Connect dependencies or data paths.
  4. 4Remove detail that distracts from the system structure.

WRITING TIPS

Keep the diagram useful

Use blocks for concepts, not every implementation detail.

Keep connections directional where possible.

FAQ

Frequently asked questions

What is a block diagram useful for?+

Block diagrams communicate high-level structure when the audience needs the major components and relationships first.

How detailed should a block diagram be?+

Use one block per meaningful concept and move implementation detail into a more specific diagram.

TEMPLATES

Start from a related template

Platform block architecture

Arrange the major blocks that make up a platform.

Open template

RELATED DIAGRAMS

Explore another Mermaid diagram

Mermaid flowchart

Visualize processes, decisions, and system flows with connected nodes.

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Mermaid sequence diagram

Map requests, responses, and asynchronous events between services.

Read the guide

Mermaid class diagram

Design domain objects, properties, methods, inheritance, and relationships.

Read the guide

Mermaid ER diagram

Document database entities, fields, relationships, and cardinality.

Read the guide

Mermaid state diagram

Show how an object or workflow changes state in response to events.

Read the guide

Mermaid mindmap

Organize ideas and subtopics hierarchically around a central theme.

Read the guide

Ready to make a Block?

Open the editor with a working example and adapt it to your project.

Start in Mermaid Studio