---
id: diagrams
title: Diagrams
description: Writing diagrams with Mermaid
slug: /markdown-features/diagrams
---

# Diagrams

Diagrams can be rendered using [Mermaid](https://mermaid-js.github.io/mermaid/) in a code block.

## Installation {#installation}

```bash npm2yarn
npm install --save @docusaurus/theme-mermaid
```

Enable Mermaid functionality by adding plugin `@docusaurus/theme-mermaid` and setting `markdown.mermaid` to `true` in your `docusaurus.config.js`.

```js title="docusaurus.config.js"
export default {
  markdown: {
    mermaid: true,
  },
  themes: ['@docusaurus/theme-mermaid'],
};
```

## Usage {#usage}

Add a code block with language `mermaid`:

````md title="Example Mermaid diagram"
```mermaid
graph TD;
    A-->B;
    A-->C;
    B-->D;
    C-->D;
```
````

```mermaid
graph TD;
    A-->B;
    A-->C;
    B-->D;
    C-->D;
```

See the [Mermaid syntax documentation](https://mermaid-js.github.io/mermaid/#/./n00b-syntaxReference) for more information on the Mermaid syntax.

## Theming {#theming}

The diagram dark and light themes can be changed by setting `mermaid.theme` values in the `themeConfig` in your `docusaurus.config.js`. You can set themes for both light and dark mode.

```js title="docusaurus.config.js"
export default {
  themeConfig: {
    mermaid: {
      theme: {light: 'neutral', dark: 'forest'},
    },
  },
};
```

See the [Mermaid theme documentation](https://mermaid-js.github.io/mermaid/#/theming) for more information on theming Mermaid diagrams.

## Mermaid Config {#configuration}

Options in `mermaid.options` will be passed directly to `mermaid.initialize`:

```js title="docusaurus.config.js"
export default {
  themeConfig: {
    mermaid: {
      options: {
        maxTextSize: 50,
      },
    },
  },
};
```

See the [Mermaid config documentation](https://mermaid-js.github.io/mermaid/#/./Setup?id=configuration) and the [Mermaid config types](https://github.com/mermaid-js/mermaid/blob/master/packages/mermaid/src/config.type.ts) for the available config options.
