PlantUML vs Mermaid which is the best Diagramming Tools

PlantUML vs Mermaid: Visual representations play a crucial role in understanding complex concepts, processes, and systems. When it comes to creating diagrams, two popular tools frequently come up in discussions: PlantUML and Mermaid. Both tools offer powerful features for creating diagrams, but they cater to different preferences and requirements. In this blog post, we’ll delve into the features of PlantUML and Mermaid, compare them, and help you decide which one suits your needs better.

What are the key differences between PlantUML and Mermaid diagramming tools?

PlantUML offers a wide range of diagram types with a textual syntax, ideal for extensive customization and integration. Mermaid, on the other hand, utilizes a markdown-like syntax, providing real-time rendering and interactivity. Choose PlantUML for versatility, or Mermaid for simplicity and dynamic visualization.

PlantUML Overview:

PlantUML is a versatile open-source tool for creating diagrams using simple textual descriptions. It supports various diagram types, including UML diagrams, sequence diagrams, class diagrams, activity diagrams, and more. PlantUML uses a domain-specific language (DSL) to define diagrams, making it easy to generate diagrams from plain text.

Key Features of PlantUML:

  1. Textual Syntax: With PlantUML, diagrams are defined using a simple and intuitive textual syntax, which allows for easy editing and version control.
  2. Extensive Diagram Support: PlantUML supports a wide range of diagram types, making it suitable for various diagramming needs.
  3. Customization Options: Users can customize the appearance of diagrams by adjusting styles, colors, and layouts.
  4. Integration: PlantUML can be integrated with various text editors, IDEs, and documentation tools, making it convenient for developers and technical writers.
  5. Output Formats: PlantUML can generate diagrams in multiple formats, including PNG, SVG, PDF, and LaTeX.

Mermaid Overview:

Mermaid is another popular open-source diagramming tool that focuses on creating diagrams using a markdown-like syntax. It is primarily used for creating flowcharts, sequence diagrams, Gantt charts, and other diagram types commonly used in software development and project management.

Key Features of Mermaid:

  1. Markdown Syntax: Mermaid uses a markdown-like syntax to define diagrams, which is familiar to many developers and writers.
  2. Real-time Rendering: Mermaid provides real-time rendering of diagrams, allowing users to see changes instantly as they edit the diagram code.
  3. Interactivity: Mermaid supports interactive diagrams with features like zooming, panning, and tooltips.
  4. Diagram Generation: Mermaid can generate diagrams directly in the browser or as static images for offline use.
  5. Version Control: Since Mermaid diagrams are defined using text, they can be easily versioned and managed using version control systems like Git.

Comparison table of PlantUML vs Mermaid

Features PlantUML Mermaid
Syntax Textual DSL Markdown-like syntax
Diagram Types Wide range including UML, sequence, class, etc. Primarily flowcharts, sequence diagrams, and more
Customization Moderate customization options Limited customization capabilities
Integration Integration with various editors and tools Limited integration options
Real-time Rendering No real-time rendering Real-time rendering in the browser
Interactivity Limited interactivity Supports interactive diagrams
Version Control Version control supported through text files Version control supported through text files

Based on the comparison above, PlantUML is preferable for users who require a wide range of diagram types, extensive customization options, and integration with various tools. On the other hand, Mermaid is suitable for those who prefer a markdown-like syntax, real-time rendering, and interactive diagrams.

Use cases of PlantUML vs Mermaid

Use Cases of PlantUML:

  1. Software Development: PlantUML is commonly used for creating UML diagrams such as class diagrams, sequence diagrams, and activity diagrams, making it ideal for software design and architecture documentation.
  2. System Modeling: With its support for various diagram types, PlantUML is suitable for modeling complex systems, including system architecture diagrams, component diagrams, and deployment diagrams.
  3. Documentation: PlantUML’s textual syntax makes it easy to embed diagrams directly into documentation, such as software requirements specifications, technical documentation, and README files.
  4. Collaboration: Teams can collaborate effectively using PlantUML, as diagrams can be versioned and shared via version control systems like Git, facilitating communication and understanding among team members.

Use Cases of Mermaid:

  1. Web Development: Mermaid’s markdown-like syntax and real-time rendering make it a popular choice for creating flowcharts, sequence diagrams, and Gantt charts in web development projects, aiding in visualizing project workflows and timelines.
  2. Project Management: Mermaid’s interactive features and support for Gantt charts make it well-suited for project management tasks, such as planning project schedules, tracking progress, and identifying dependencies.
  3. Education and Training: Mermaid’s simplicity and dynamic visualization capabilities make it an excellent tool for educational purposes, including teaching programming concepts, illustrating algorithms, and explaining complex processes.
  4. Presentations: Mermaid’s real-time rendering allows presenters to create and modify diagrams on-the-fly during presentations, enhancing audience engagement and understanding of complex topics.

External Links

PlantUML Official Website

Mermaid Official Documentation

Frequently Asked Questions (FAQs):

Can PlantUML and Mermaid diagrams be used together?

Yes, PlantUML and Mermaid diagrams can be used together in the same project. However, you’ll need to manage them separately as they use different syntax and rendering engines.

Are there any limitations to using PlantUML or Mermaid?

Both tools have their limitations. PlantUML’s customization options may not be as extensive as some other diagramming tools, while Mermaid’s diagram types are more focused on specific use cases.

Can I export diagrams created with PlantUML or Mermaid to other formats?

Yes, both PlantUML and Mermaid support exporting diagrams to various formats such as PNG, SVG, PDF, and others.


Choosing between PlantUML and Mermaid depends on your specific requirements and preferences. If you need a wide range of diagram types and extensive customization options, PlantUML may be the better choice. However, if you prefer a markdown-like syntax, real-time rendering, and interactive diagrams, Mermaid could be more suitable. Ultimately, both tools are powerful options for creating diagrams and can be used effectively depending on your needs.

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