DGMO vs the rest

Syntax, features, and rendering, side by side.

Feature comparison

How the four tools stack up across key capabilities.

Feature	DGMO	Mermaid	D2	PlantUML
Sequence diagrams	✓	✓	✓	✓
Flowcharts	✓	✓	✓	✓
Data charts (bar, line, pie...)	23 types	4 types	—	—
Interactive / clickable output	✓	—	—	—
No boilerplate / wrappers	✓	—	—	—
CLI tool	✓	✓	✓	✓
MCP / AI integration	✓	—	—	—
GitHub native rendering	—	✓	—	—
Dark theme built-in	✓	Config	—	—
Color palettes (one-line switch)	10 palettes	CSS overrides	—	—
Price	Free	Free	Free	Free

Chart type support

Every diagram and chart type across all four tools — including types not yet supported by DGMO.

Type	DGMO	Mermaid	D2	PlantUML
Diagrams
Activity / BPMN	—	—	—	✓
Boxes & lines	✓	—	—	—
C4 (architecture model)	✓	✓	—	Via library
Class	✓	✓	✓	✓
Component / deployment	—	—	—	✓
ER (entity-relationship)	✓	✓	✓	✓
Flowchart	✓	✓	✓	✓
Git graph	—	✓	—	—
Infrastructure / network	✓	Beta	✓	Via nwdiag
Kanban	✓	✓	—	—
Mindmap	✓	✓	—	✓
Org chart	✓	—	—	✓
Requirement	—	✓	—	—
Sequence	✓	✓	✓	✓
Sitemap	✓	—	—	—
State	✓	✓	—	✓
Timing	—	—	—	✓
Use case	—	—	—	✓
User journey	✓	✓	—	—
Wireframe	✓	—	—	Via Salt
Data & visualization
Arc diagram	✓	—	—	—
Area	✓	—	—	—
Bar / stacked bar	✓	Via XY chart	—	—
Chord	✓	—	—	—
Cycle	✓	—	—	—
Function plot	✓	—	—	—
Funnel	✓	—	—	—
Gantt	✓	✓	—	✓
Heatmap	✓	—	—	—
Line / multi-line	✓	Via XY chart	—	—
Pie / doughnut	✓	✓	—	—
Polar area	✓	—	—	—
Quadrant	✓	✓	—	—
Radar	✓	—	—	—
Sankey	✓	✓	—	—
Scatter	✓	—	—	—
Slope chart	✓	—	—	—
Tech radar	✓	—	—	—
Timeline	✓	✓	—	—
Venn	✓	—	—	—
Word cloud	✓	—	—	—

Sequence diagram

The same checkout flow in all four languages. DGMO infers participant types from names — User becomes a stick figure, WebApp renders as a frontend, DB becomes a cylinder. Mermaid and PlantUML force you to declare every participant up front before you can use it.

DGMO 10 lines

sequence Checkout

User -checkout-> WebApp
WebApp -POST /orders-> API
API -charge card-> Stripe
Stripe -charge_id-> API
API -save order-> DB
DB -ok-> API
API -receipt-> WebApp
WebApp -confirmation-> User

Mermaid 15 lines

sequenceDiagram
    actor User
    participant WebApp
    participant API
    participant Stripe
    participant DB

    User->>WebApp: checkout
    WebApp->>API: POST /orders
    API->>Stripe: charge card
    Stripe-->>API: charge_id
    API->>DB: save order
    DB-->>API: ok
    API-->>WebApp: receipt
    WebApp-->>User: confirmation

D2 10 lines

shape: sequence_diagram

User -> WebApp: checkout
WebApp -> API: POST /orders
API -> Stripe: charge card
Stripe -> API: charge_id
API -> DB: save order
DB -> API: ok
API -> WebApp: receipt
WebApp -> User: confirmation

PlantUML 16 lines

@startuml
actor User
participant WebApp
participant API
participant Stripe
database DB

User -> WebApp: checkout
WebApp -> API: POST /orders
API -> Stripe: charge card
Stripe --> API: charge_id
API -> DB: save order
DB --> API: ok
API --> WebApp: receipt
WebApp --> User: confirmation
@enduml

Flowchart

A decision flow. DGMO infers shapes from brackets — no manual declarations needed.

DGMO 6 lines

flowchart

[Request] -> <Authenticated?>
  -yes-> [Load Dashboard]
  -no-> /Show Login/
/Show Login/ -> [Enter Credentials] -> <Authenticated?>

Mermaid 6 lines

flowchart TD
    A[Request] --> B{Authenticated?}
    B -->|Yes| C[Load Dashboard]
    B -->|No| D[Show Login]
    D --> E[Enter Credentials]
    E --> B

D2 7 lines

Request -> Authenticated?
Authenticated? -> Load Dashboard: Yes
Authenticated? -> Show Login: No
Show Login -> Enter Credentials
Enter Credentials -> Authenticated?

Authenticated?.shape: diamond

PlantUML 12 lines

@startuml
start
:Request;
if (Authenticated?) then (Yes)
  :Load Dashboard;
else (No)
  :Show Login;
  :Enter Credentials;
  :Retry;
endif
stop
@enduml

Class diagram

An abstract shape hierarchy. DGMO uses natural keywords — extends, [abstract] — instead of arrows.

DGMO 14 lines

class

Shape [abstract]
  +area(): number

Circle
  -radius: number

Rectangle
  -width: number
  -height: number

Circle extends Shape
Rectangle extends Shape

Mermaid 14 lines

classDiagram
    class Shape {
        <<abstract>>
        +area() number
    }
    class Circle {
        -radius: number
    }
    class Rectangle {
        -width: number
        -height: number
    }
    Circle --|> Shape
    Rectangle --|> Shape

D2 18 lines

MyShape: {
  shape: class
  +area(): number
}

MyCircle: {
  shape: class
  -radius: number
}

MyRectangle: {
  shape: class
  -width: number
  -height: number
}

MyCircle -> MyShape: extends
MyRectangle -> MyShape: extends

PlantUML 17 lines

@startuml
abstract class Shape {
    +area(): number
}

class Circle {
    -radius: number
}

class Rectangle {
    -width: number
    -height: number
}

Circle --|> Shape
Rectangle --|> Shape
@enduml

When to use what

Honest recommendations. Every tool has its strengths.

DGMO

Concise syntax, beautiful rendering, interactive presentations, data charts

If you want the least boilerplate, dark-themed output, and a single language for both diagrams and data charts, DGMO is built for that.

Mermaid

GitHub/GitLab native rendering, maximum community support

If your diagrams live in GitHub READMEs or you need the largest ecosystem of integrations, Mermaid is the established choice.

D2

Container and architecture diagrams with auto-layout

D2 excels at nested container layouts and has a polished Go CLI. Great for infrastructure and architecture diagrams.

PlantUML

Existing team usage, deep IDE integrations, UML-strict diagrams

PlantUML has decades of history and integrations. If your team already uses it, switching may not be worth it.

Where DGMO is weaker

No tool wins everywhere. Here's where the alternatives are honestly stronger.

GitHub / GitLab native rendering — Mermaid wins

Mermaid renders inline in GitHub READMEs, issues, PRs, and GitLab. DGMO doesn't — you have to render to SVG or PNG with the CLI and embed the image. If your diagrams live in markdown that's read on GitHub, Mermaid is the lower-friction choice.

UML-strict diagrams (use case, BPMN, activity, deployment) — PlantUML wins

PlantUML supports the full UML 2.x catalog plus BPMN, activity diagrams, deployment diagrams, and timing diagrams. DGMO covers the practical subset (sequence, class, state, ER, C4) but doesn't aim to be a UML-complete tool. If your team is committed to UML formality, PlantUML is decades-deep.

Auto-layout for nested container architectures — D2 wins

D2's layout engines (ELK, Dagre, TALA) handle deeply-nested container/group hierarchies more elegantly than DGMO. If you're drawing complex architecture diagrams with multiple levels of grouping, D2's auto-layout is more polished.

Frequently asked questions

What is the difference between DGMO and Mermaid?

DGMO uses a more concise syntax with less boilerplate, supports 20+ data chart types (bar, line, pie, scatter, etc.) that Mermaid lacks, and produces interactive SVG output with click-to-source navigation. Mermaid has broader ecosystem support including native rendering in GitHub and GitLab.

Is DGMO free?

Yes — everything is free. The CLI, npm library, online editor, MCP server, and desktop app are all free to use with no trial or subscription.

Can I use DGMO in GitHub READMEs?

Not natively — GitHub only renders Mermaid diagrams inline. You can use the dgmo CLI in CI to render diagrams to SVG or PNG and embed the images in your README.

Does DGMO support dark mode?

Yes. DGMO has built-in dark and light themes, plus 10 color palettes (Nord, Catppuccin, Solarized, Gruvbox, Tokyo Night, Rose Pine, One Dark, Bold, Dracula, and Monokai).