Format code

Adding code samples

You can add inline code snippets or code blocks. Code blocks support meta options for syntax highlighting, titles, line highlighting, icons, and more.

Inline code

To denote a word or phrase as code, enclose it in backticks (`).

To denote a `word` or `phrase` as code, enclose it in backticks (`).

Code blocks

Use fenced code blocks by enclosing code in three backticks. Code blocks are copyable, and if you have the assistant enabled, users can ask AI to explain the code.

Specify the programming language for syntax highlighting and to enable meta options. Add any meta options, like a title or icon, after the language.

class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello, World!");
  }
}

```java HelloWorld.java
class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello, World!");
  }
}
```

Code block options

Add meta options to your code blocks to customize their appearance.

Option syntax

• String and boolean options: Wrap with "", '', or no quotes.
• Expression options: Wrap with {}, "", or ''.

Syntax highlighting

Enable syntax highlighting by specifying the programming language after the opening backticks of a code block.

We use Shiki for syntax highlighting and support all available languages. See the full list of languages in Shiki's documentation.

Customize code block themes globally using styling.codeblocks in your config.json file. Set simple themes like system or dark, or configure custom Shiki themes for light and dark modes. See Settings for configuration options.

class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello, World!");
  }
}

```java Syntax highlighting example
class HelloWorld {
  public static void main(String[] args) {
    System.out.println("Hello, World!");
  }
}
```

Twoslash

In JavaScript and TypeScript code blocks, use twoslash to enable interactive type information. Users can hover over variables, functions, and parameters to see types and errors like in an IDE.

type Pet = "cat" | "dog" | "hamster";

function adoptPet(name: string, type: Pet) {
  return `${name} the ${type} is now adopted!`;
}

// Hover to see the inferred types
const message = adoptPet("Luna", "cat");

```ts twoslash Twoslash example
type Pet = "cat" | "dog" | "hamster";

function adoptPet(name: string, type: Pet) {
  return `${name} the ${type} is now adopted!`;
}

// Hover to see the inferred types
const message = adoptPet("Luna", "cat");
```

Title

Add a title to label your code example. Use title="Your title" or a string on a single line.

const hello = "world";

```javascript Title example
const hello = "world";
```

Icon

Add an icon to your code block using the icon property. See Icons for all available options.

<CodeBlock language="javascript" filename="app.js" icon="file-code">
{`const hello = "world";`}
</CodeBlock>

Line highlighting

Highlight specific lines using the <CodeBlock> component with the highlight prop. Specify line numbers and ranges like "{1,3-5}".

<CodeBlock language="javascript" filename="highlight.js" highlight="{1,2,5}">
{`const greeting = "Hello, World!";
function sayHello() {
  console.log(greeting);
}
sayHello();`}
</CodeBlock>

Line focusing

Focus on specific lines using the <CodeBlock> component with the focus prop. Non-focused lines will be dimmed.

<CodeBlock language="javascript" filename="focus.js" focus="{2,3}">
{`const greeting = "Hello, World!";
function sayHello() {
  console.log(greeting);
}
sayHello();`}
</CodeBlock>

Show line numbers

Display line numbers on the left side of your code block using the <CodeBlock> component with the lines prop.

<CodeBlock language="javascript" filename="example.js" lines>
{`const greeting = "Hello, World!";
function sayHello() {
  console.log(greeting);
}
sayHello();`}
</CodeBlock>

Expandable

Allow users to expand and collapse long code blocks using the <CodeBlock> component with the expandable prop.

<CodeBlock language="python" filename="library.py" expandable>
{`from datetime import datetime, timedelta
...
if __name__ == "__main__":
  main()`}
</CodeBlock>

Wrap

Enable text wrapping for long lines using the <CodeBlock> component with the wrap prop. This prevents horizontal scrolling and makes long lines easier to read.

<CodeBlock language="javascript" filename="wrap.js" wrap>
{`const greeting = "Hello, World! I am a very long line...";`}
</CodeBlock>

Diff

Show a visual diff of added or removed lines in your code blocks. Added lines are highlighted in green and removed lines are highlighted in red.

Use the <CodeBlock> component with the diff prop to auto-detect lines starting with + or -:

<CodeBlock language="javascript" filename="config.js" diff>
{`const config = {
-  debug: true,
+  debug: false,
  timeout: 5000,
};`}
</CodeBlock>

Or use the add and remove props with line numbers for explicit control:

<CodeBlock language="javascript" add="{1,4}" remove="{3}">
{`...`}
</CodeBlock>

CodeBlock component

Use the <CodeBlock> component in custom React components to programmatically render code blocks with the same styling and features as markdown code blocks.

Props

Example

export const CustomCodeBlock = ({ filename, icon, language, highlight, children }) => {
  return (
    <CodeBlock
      filename={filename}
      icon={icon}
      language={language}
      lines
      highlight={highlight}
    >
      {children}
    </CodeBlock>
  );
};