Raw HTML

Use inline HTML for advanced formatting when Markdown syntax is not sufficient. HTML is processed through rehype-raw and sanitized for security.

Overview

Unmarkdown supports a subset of HTML tags embedded directly in your Markdown via rehype-raw. All HTML is sanitized through rehype-sanitize with a custom schema that balances functionality and security.

Allowed Elements

Text Formatting

<strong>, <em>: Bold and italic
<mark>: Highlighted text
<del>, <ins>: Deleted and inserted text
<sup>, <sub>: Superscript and subscript
<kbd>: Keyboard key caps

Structure

<details>, <summary>: Collapsible content sections
<section>: Semantic sections
<br>, <hr>: Line breaks and horizontal rules
<colgroup>, <col>: Table column styling

Media and SVG

<img>: Images with src, alt, width, height attributes
<svg> and children (<path>, <circle>, <line>, <polyline>, <rect>): Inline SVG graphics

Tables

<table>, <thead>, <tbody>, <tr>, <th>, <td>: Full table support

Lists and Semantic

<ul>, <ol>, <li>: Lists
<abbr>, <cite>, <dfn>, <time>: Semantic elements
<input>: Checkbox inputs (for task lists)

Allowed Attributes

The following attributes are permitted on HTML elements:

style: Inline styles (partially supported, may be stripped in some export destinations)
class: CSS class names
dir: Text direction (ltr, rtl)
aria-*: Accessibility attributes
data-*: Custom data attributes
SVG attributes: stroke, fill, viewBox, width, height, d (on path), and other SVG-specific attributes

Blocked Elements

The following elements and attributes are stripped during rendering for security:

<script>: JavaScript execution
<style>: CSS injection
<iframe>: Embedded frames
<embed>, <object>, <applet>: Plugin content
<form>: Form elements (except input for task lists)
on* event handlers: onclick, onload, onerror, etc.

Warning

Any element or attribute not in the allow list is silently removed during rendering. This includes JavaScript URLs (javascript:) in href attributes.

Practical Examples

Collapsible Sections

markdown

<details>
<summary>Click to expand</summary>

This content is hidden by default and revealed when the user
clicks the summary. You can include **Markdown** inside.

- List items work
- `Code` works too

</details>

Keyboard Shortcuts

markdown

Press <kbd>Cmd</kbd> + <kbd>Shift</kbd> + <kbd>P</kbd> to publish.

HTML Tables with Spanning

When you need cell spanning or more complex table layouts than Markdown tables support:

html

<table>
  <thead>
    <tr>
      <th>Feature</th>
      <th>Free</th>
      <th>Pro</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Documents</td>
      <td>3</td>
      <td>Unlimited</td>
    </tr>
    <tr>
      <td>Templates</td>
      <td>8</td>
      <td>62</td>
    </tr>
  </tbody>
</table>

Text Direction

html

<p dir="rtl">This text renders right-to-left for Arabic or Hebrew content.</p>

Export Compatibility

Raw HTML is rendered faithfully when publishing to the web. When exporting to other destinations, HTML elements are converted to the closest equivalent format:

Google Docs and Word: Most HTML elements have direct equivalents
Slack: Limited to text formatting (bold, italic, strikethrough, code)
Email: Most HTML preserved, but rendering depends on the email client
Plain Text: HTML tags are stripped, only text content remains

Emoji and Icons Content Limits