Mermaid
Generate diagrams and flowcharts from markdown-like text.
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Self-host it
Run the open-source version on your own infrastructure.
What is Mermaid?
Mermaid is an open-source diagramming and charting tool that enables users to generate visual representations of workflows, processes, and data relationships using a simple text-based syntax. Its primary purpose is to streamline the creation of diagrams such as flowcharts, sequence diagrams, and other visual artifacts by allowing users to write code-like text that is rendered into graphical outputs. This tool is widely adopted by developers, data engineers, analysts, educators, and technical writers who need to document complex systems or processes without requiring specialized design software. Mermaid addresses the challenge of creating diagrams that are both precise and easily modifiable, offering a lightweight alternative to traditional diagramming tools that often involve manual drawing or complex software interfaces.
How it works
Mermaid is a JavaScript library that converts textual descriptions into diagrams and charts, hosted on mermaid.ai and maintained as an open-source project. It simplifies the process of visualizing workflows by allowing users to describe diagrams in a markdown-like format, which is then rendered into visual elements. The tool is designed for developers and technical professionals who need to create diagrams for documentation, collaboration, or presentation. Its text-based approach ensures diagrams are version-controlled, shareable, and easily integrated into code repositories or web content. Mermaid supports a variety of diagram types, including flowcharts, sequence diagrams, class diagrams, and state diagrams. For example, a flowchart can be created using keywords like `start`, `decision`, and `end`, with arrows and labels defining the workflow. Sequence diagrams can illustrate interactions between objects in a system, using vertical lanes and horizontal messages.
How to use it
- 1Write a textual description of the diagram using Mermaid's syntax. For example: `graph TD A[Start] --> B(Decision) B --> C[Option 1] B --> D[Option 2]`.
- 2Use the Mermaid Live Editor (available at mermaid.ai) to input the text and view the rendered diagram in real-time. Alternatively, integrate Mermaid into a web application by including its JavaScript library.
- 3Export the diagram as an image or embed it directly into HTML, Markdown, or LaTeX documents. The tool automatically handles formatting and rendering based on the input text.
- 4Save or share the textual code for version control, ensuring diagrams remain editable and reproducible.
What it can do
- diagrams from text
Use cases
Assumptions and limitations
Assumptions
- source: https://github.com/mermaid-js/mermaid
- license: MIT — free to use
- privacy: Self-hosted — you control your data
Limitations
- Limited support for highly complex or custom diagram types
- Requires basic familiarity with text-based syntax for diagram creation
- Dependent on JavaScript execution environments for rendering
- May lack real-time collaboration features compared to dedicated diagramming tools
- Limited built-in styling options for advanced visual customization
Understanding the result
Generate diagrams and flowcharts from markdown-like text.
Tool details
- Clearly flagged when a network request is needed.
- No account, no sign-up, and no tracking of your content.
- Powered by (MIT).
- Built with
- (mermaid-js/mermaid)
- License
- MIT
- Runs locally
- No — requires a network request
- Verification
- Not yet verified
- Input
- Query
- Output
- Text
Built with mermaid-js/mermaid. OpenToolVault provides the discovery and browser interface while crediting the original project maintainers.
- Built with
- License
- MIT
Open-source project
OpenToolVault is an independent directory. We are not affiliated with or endorsed by this project.
References
- / — GitHub Repository
Upstream project · GitHub
- MIT License
Upstream project
Frequently asked
What types of diagrams can Mermaid generate?
Mermaid supports flowcharts, sequence diagrams, class diagrams, state diagrams, and甘特 charts. Users describe diagrams using a simple text syntax, which is then rendered into visual outputs. For example, a flowchart can be created using keywords like `start`, `decision`, and `end`, with arrows and labels defining the workflow.
How does Mermaid process text into diagrams?
Mermaid uses a JavaScript parser to interpret text-based descriptions written in a markdown-like syntax. When the text is processed, it is converted into an abstract syntax tree, which is then rendered into SVG or PNG formats using a rendering engine. This allows diagrams to be generated dynamically in web browsers or integrated into applications that support Mermaid's library.
How do I create a basic flowchart with Mermaid?
To create a flowchart, start by defining the diagram type and nodes. For example: `graph TD A[Start] --> B(Decision) B --> C[Option 1] B --> D[Option 2]`. Input this code into the Mermaid Live Editor or an integrated development environment (IDE) that supports Mermaid, then view the rendered diagram. Adjust the syntax as needed to modify the structure.
How does Mermaid compare to tools like Lucidchart or draw.io?
Mermaid differs from tools like Lucidchart or draw.io by using a text-based syntax instead of a graphical interface. This makes Mermaid ideal for developers and technical teams who prefer code-centric workflows, while tools like Lucidchart offer more intuitive drag-and-drop features for non-technical users. Mermaid excels in integration with code repositories and version control systems, whereas Lucidchart and draw.io provide richer collaboration features.
What should I do if my Mermaid diagram isn't rendering?
Common issues include syntax errors, unsupported diagram types, or missing dependencies. Check for typos in the text syntax, ensure the diagram type is supported, and verify that the Mermaid library is correctly integrated into your environment. If using the Live Editor, refresh the page or reload the editor. For embedded applications, confirm that the JavaScript library is properly included and that there are no conflicts with other scripts.