Pros of mermaid

• Supports a wider variety of diagram types (flowcharts, sequence diagrams, Gantt charts, etc.)
• More active development and larger community
• Better documentation and examples

Cons of mermaid

• Steeper learning curve due to more complex syntax
• Larger file size and potentially slower rendering for simple diagrams

Code Comparison

mermaid:

graph TD
    A[Start] --> B{Is it?}
    B -->|Yes| C[OK]
    B -->|No| D[End]

flowchart.js:

st=>start: Start
e=>end: End
op=>operation: My Operation
cond=>condition: Yes or No?

st->op->cond
cond(yes)->e
cond(no)->op

Both libraries allow for creating flowcharts, but mermaid's syntax is more concise and supports a wider range of diagram types. flowchart.js focuses specifically on flowcharts and uses a different syntax with explicit connections between nodes.

mermaid offers more flexibility and features, making it suitable for complex diagramming needs across various types. However, flowchart.js may be simpler to use for basic flowcharts and could have a gentler learning curve for newcomers to diagramming libraries.

The choice between the two depends on the specific requirements of your project, such as the types of diagrams needed, the complexity of the charts, and the desired level of customization.

Pros of draw.io

• More comprehensive diagramming tool with support for various diagram types beyond flowcharts
• Rich set of features including real-time collaboration and integration with cloud storage services
• User-friendly interface with drag-and-drop functionality and extensive shape libraries

Cons of draw.io

• Larger codebase and more complex setup compared to flowchart.js
• May be overkill for simple flowchart needs, with a steeper learning curve
• Requires more resources to run, potentially impacting performance on low-end devices

Code Comparison

draw.io (JavaScript):

var graph = new mxGraph(container);
var parent = graph.getDefaultParent();
graph.getModel().beginUpdate();
try {
  var v1 = graph.insertVertex(parent, null, 'Hello', 20, 20, 80, 30);
  var v2 = graph.insertVertex(parent, null, 'World!', 200, 150, 80, 30);
  var e1 = graph.insertEdge(parent, null, '', v1, v2);
} finally {
  graph.getModel().endUpdate();
}

flowchart.js:

var chart = flowchart.parse('st=>start: Start\n' +
                            'e=>end: End\n' +
                            'op=>operation: My Operation\n' +
                            'cond=>condition: Yes or No?\n' +
                            'st->op->cond\n' +
                            'cond(yes)->e\n' +
                            'cond(no)->op');
chart.drawSVG('canvas');

Pros of PlantUML

• Supports a wide variety of diagram types beyond just flowcharts
• Text-based syntax allows for version control and easy collaboration
• Integrates well with various IDEs and documentation tools

Cons of PlantUML

• Steeper learning curve for its syntax compared to flowchart.js
• Requires Java runtime environment for local rendering
• Less customizable in terms of visual styling without advanced configuration

Code Comparison

PlantUML:

@startuml
start
:Step 1;
if (condition) then (yes)
  :Step 2;
else (no)
  :Step 3;
endif
:Step 4;
stop
@enduml

flowchart.js:

var chart = flowchart.parse(`
st=>start: Start
e=>end: End
op1=>operation: Step 1
cond=>condition: Condition?
op2=>operation: Step 2
op3=>operation: Step 3

st->op1->cond
cond(yes)->op2->e
cond(no)->op3->e
`);
chart.drawSVG('diagram');

Both libraries offer ways to create flowcharts, but PlantUML uses a more compact, text-based syntax while flowchart.js employs a JavaScript-based approach with a different syntax structure. PlantUML's versatility in diagram types is evident, while flowchart.js focuses specifically on flowcharts with a more accessible syntax for web developers.

Pros of Excalidraw

• More feature-rich, offering a complete drawing and diagramming solution
• Provides a modern, intuitive user interface for creating diagrams
• Supports collaborative editing in real-time

Cons of Excalidraw

• Larger file size and potentially more complex to integrate
• May be overkill for simple flowchart needs
• Steeper learning curve for basic usage

Code Comparison

Flowchart.js:

var chart = flowchart.parse('st=>start: Start|past:>http://www.google.com[blank]\n' +
                            'e=>end: End:>http://www.google.com\n' +
                            'op1=>operation: My Operation|past\n' +
                            'op2=>operation: Stuff|current\n' +
                            'sub1=>subroutine: My Subroutine|invalid\n' +
                            'cond=>condition: Yes \n' +
                            'or No?|approved:>http://www.google.com\n' +
                            'c2=>condition: Good idea|rejected\n' +
                            'io=>inputoutput: catch something...|request\n');
chart.drawSVG('canvas');

Excalidraw:

import { exportToBlob } from "@excalidraw/excalidraw";

const blob = await exportToBlob({
  elements,
  appState,
  files,
  mimeType: "image/png",
});

While Flowchart.js focuses specifically on flowcharts with a simple API, Excalidraw offers a more comprehensive drawing solution with a different approach to integration and usage.

Pros of Kroki

• Supports multiple diagram types (flowcharts, sequence diagrams, etc.)
• Server-based rendering for consistent output across platforms
• Integrates with various documentation tools and frameworks

Cons of Kroki

• Requires server setup or use of a hosted service
• Potentially slower rendering due to server-side processing
• Less customization options for individual diagram types

Code Comparison

Flowchart.js:

var chart = flowchart.parse('st=>start: Start|past:>http://www.google.com[blank]\n' +
                            'e=>end: End:>http://www.google.com\n' +
                            'op1=>operation: My Operation|past\n' +
                            'op2=>operation: Stuff|current\n' +
                            'sub1=>subroutine: My Subroutine|invalid\n' +
                            'cond=>condition: Yes \nor No?|approved:>http://www.google.com\n' +
                            'io=>inputoutput: catch something...|request\n');
chart.drawSVG('canvas');

Kroki:

@startuml
Alice -> Bob: Authentication Request
Bob --> Alice: Authentication Response
Alice -> Bob: Another authentication Request
Alice <-- Bob: Another authentication Response
@enduml

Note: Kroki uses different syntax for each diagram type, while Flowchart.js focuses solely on flowcharts with its own specific syntax.