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About the developer

215 Stars 65 Forks MIT License 67 Commits 25 Opened issues


A browser extension for Chrome, Opera & Firefox that adds Mermaid language support to Github

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Github + Mermaid

A browser extension for Chrome, Opera & Firefox that adds Mermaid language support to Github Markdown.



Supported GitHub features

  • [x] Pull requests & issues description (preview + published) - Demo
  • [x] Pull requests & issues comment (preview + published)
  • [x] Markdown (
    ) files (diff + published)
  • [x] Gists - Demo

Diagram types


Flowchart example

Show source code
graph LR


A --> B[Look for an item]

B --> C{Did you find it?}
C -->|Yes| D(Stop looking)
C -->|No| E{Do you need it?}
E -->|Yes| B
E -->|No| D

Sequence Diagrams

Sequence Diagram example

Show source code
participant U as User
participant C as Client
participant S as Server
participant DB as Database

U ->> C: Fill username
U ->> C: Fill password
C ->> U: Enable "Login" button
U ->> C: Click "Login" button
C ->>+ S: POST /login
S ->>+ DB: SELECT FROM users
Note over S,DB: See for impl. details
DB -->>- S: results
S -->>- C: { authenticated: true }
C ->> U: redirect /home

Gantt Diagrams

Gantt Diagram example

Show source code
    title A Gantt Diagram
    dateFormat  YYYY-MM-DD
    section Section
    A task           :a1, 2014-01-01, 30d
    Another task     :after a1  , 20d
    section Another
    Task in sec      :2014-01-12  , 12d
    another task      : 24d

How to use

Simply put Mermaid code into ```mermaid. See Mermaid official website for more information about the Mermaid syntax.


  • [x] Initial implementation
  • [x] Publish Chrome extension
  • [x] Documentation
  • [x] Publish Firefox extension
  • [ ] Publish Opera extension
  • [x] Continuous Integration
  • [x] Upgrade dependencies
  • [x] Automatic dependency management
  • [x] Fix #3
  • [ ] Testing
  • [ ] Dark theme + option page
  • [ ] Cleanup




Contributions (issues ♥, pull requests ♥♥♥) are more than welcome! Feel free to clone, fork, modify, extend, etc.

See contributing intructions for details.

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