Mermaid vs PlantUML vs Kroki – Which Diagramming Tool Is Best for You

Mermaid vs PlantUML vs Kroki stand out as popular choices. Each offers unique features and capabilities tailored to different user needs, from software developers to business analysts. This comprehensive comparison explores their strengths, use cases, and functionalities to help you choose the right tool for your diagramming requirements.

Overview of Mermaid

Mermaid is a JavaScript-based diagramming and charting tool that allows users to create diagrams and flowcharts using a simple markdown-like syntax. It is highly versatile and supports various diagram types, including flowcharts, sequence diagrams, Gantt charts, and more. Mermaid’s diagrams are rendered directly in the browser, making it easy to integrate with web applications and documentation.

Key Features of Mermaid:

  • Markdown-like Syntax: Easy to learn and use for creating diagrams.
  • Multiple Diagram Types: Supports flowcharts, sequence diagrams, Gantt charts, and more.
  • Browser Rendering: Diagrams are rendered in real-time in the browser.
  • Integration: Can be embedded in web pages and documentation platforms.

Uses of Mermaid:

  • Software Development: Sequence diagrams and flowcharts for illustrating processes and interactions.
  • Project Management: Gantt charts for visualizing project timelines and milestones.
  • Documentation: Embedding diagrams directly into documentation for clarity and understanding.

Overview of PlantUML

PlantUML is another popular diagramming tool that uses a specialized textual DSL (Domain-Specific Language) to describe diagrams. It supports a wide range of diagram types, including UML diagrams, sequence diagrams, activity diagrams, and more. PlantUML’s strength lies in its ability to generate diagrams from text descriptions, making it suitable for version control and collaborative environments.

Key Features of PlantUML:

  • Textual DSL: Describe diagrams using a specialized syntax.
  • Wide Range of Diagrams: Supports UML diagrams, sequence diagrams, and more.
  • Version Control: Diagrams are text-based, allowing for easy versioning and collaboration.
  • Integration: Plugins available for integration with various IDEs and documentation tools.

Uses of PlantUML:

  • Software Engineering: UML diagrams for software design and architecture.
  • System Documentation: Embed diagrams in documentation to visualize system structure and interactions.
  • Collaborative Development: Version-controlled diagrams for team collaboration and review.

Overview of Kroki

Kroki is a versatile diagram rendering service that supports multiple diagramming languages and formats. It acts as a central hub for generating diagrams from textual descriptions using various rendering engines. Kroki abstracts the complexity of diagram rendering, providing a unified API for generating diagrams on demand.

Key Features of Kroki:

  • Unified API: Supports multiple diagramming languages (Mermaid, PlantUML, Graphviz, etc.).
  • Diagram Rendering: Generates diagrams from textual descriptions.
  • Wide Language Support: Supports a variety of diagramming formats and languages.
  • Customization: Allows customization of diagram styles and output formats.

Uses of Kroki:

  • Cross-Platform Compatibility: Generate diagrams in different formats for web and desktop applications.
  • API Integration: Embed diagram generation in web services and documentation platforms.
  • On-Demand Rendering: Generate diagrams dynamically based on user input or API calls.

Comparison Table: Mermaid vs PlantUML vs Kroki

Feature Mermaid PlantUML Kroki
Syntax Markdown-like Textual DSL Textual descriptions (API)
Diagram Types Flowcharts, sequence diagrams, Gantt charts, more UML diagrams, sequence diagrams, more Various (Mermaid, PlantUML, Graphviz, etc.)
Rendering Browser Image (PNG, SVG, etc.) Image (PNG, SVG, etc.)
Integration Web applications, documentation IDEs, documentation tools Web services, documentation platforms
Version Control No Yes Yes
Customization Limited Moderate Yes

Uses and Applications

  • Mermaid is ideal for web developers and technical writers who need quick, browser-rendered diagrams integrated into documentation and web applications.
  • PlantUML suits software engineers and architects working in collaborative environments where version control and textual representation are crucial.
  • Kroki offers flexibility and centralized diagram generation via APIs, suitable for integrating diagram rendering into various applications and services dynamically.

Frequently Asked Questions (FAQs)

Q1: Which tool is better for generating UML diagrams?

  • PlantUML is specifically designed for creating UML diagrams efficiently from textual descriptions, making it a preferred choice for software architects and developers.

Q2: Can I use Mermaid diagrams offline?

  • Yes, Mermaid diagrams can be generated offline once the necessary libraries are installed or cached in the browser.

Q3: How customizable are diagrams generated by Kroki?

  • Kroki allows customization of diagram styles and output formats through its API, providing flexibility in diagram presentation.


Choosing the right diagramming tool depends on your specific needs and preferences. Mermaid excels in simplicity and web integration, PlantUML in textual representation and version control, and Kroki in versatility and API-driven diagram generation. Whether you’re a developer, architect, or documentarian, each tool offers unique features to enhance your diagramming experience. Evaluate based on your workflow, collaboration requirements, and integration preferences to find the tool that best suits your needs.

Supercharge Your Collaboration: Must-Have Microsoft Teams Plugins Top 7 data management tools Top 9 project management tools Top 10 Software Testing Tools Every QA Professional Should Know 9 KPIs commonly tracked closely in Manufacturing industry