Headings and Table of contents
Markdown headings
You can use regular Markdown headings.
## Level 2 title
### Level 3 title
#### Level 4 title
Each Markdown heading will appear as a table of contents entry.
Heading IDs
Each heading has an ID that can be automatically generated or explicitly specified. Heading IDs allow you to link to a specific document heading in Markdown or JSX:
[link](#heading-id)
<Link to="#heading-id">link</Link>
By default, Docusaurus will generate heading IDs for you, based on the heading text. For example, ### Hello World will have ID hello-world.
Generated IDs have some limitations:
- The ID might not look good
- You might want to change or translate the text without updating the existing ID
A special Markdown syntax lets you set an explicit heading id:
### Hello World {#my-explicit-id}
Use the write-heading-ids CLI command to add explicit IDs to all your Markdown documents.
Generated heading IDs will be guaranteed to be unique on each page, but if you use custom IDs, make sure each one appears exactly once on each page, or there will be two DOM elements with the same ID, which is invalid HTML semantics, and will lead to one heading being unlinkable.
Table of contents heading level
Each Markdown document displays a table of contents on the top-right corner. By default, this table only shows h2 and h3 headings, which should be sufficient for an overview of the page structure. In case you need to change the range of headings displayed, you can customize the minimum and maximum heading level — either per page or globally.
To set the heading level for a particular page, use the toc_min_heading_level and toc_max_heading_level front matter.
---
# Display h2 to h5 headings
toc_min_heading_level: 2
toc_max_heading_level: 5
---
To set the heading level for all pages, use the themeConfig.tableOfContents option.
module.exports = {
themeConfig: {
tableOfContents: {
minHeadingLevel: 2,
maxHeadingLevel: 5,
},
},
};
If you've set the options globally, you can still override them locally via front matter.
The themeConfig option would apply to all TOC on the site, including inline TOC, but front matter options only affect the top-right TOC. You need to use the minHeadingLevel and maxHeadingLevel props to customize each <TOCInline /> component.
Inline table of contents
It is also possible to display an inline table of contents directly inside a Markdown document, thanks to MDX.
The toc variable is available in any MDX document and contains all the headings of an MDX document. By default, only h2 and h3 headings are displayed in the TOC. You can change which heading levels are visible by setting minHeadingLevel or maxHeadingLevel for individual TOCInline components.
import TOCInline from '@theme/TOCInline';
<TOCInline toc={toc} />
The toc global is just a list of heading items:
declare const toc: {
value: string;
id: string;
level: number;
}[];
Note that the toc global is a flat array, so you can easily cut out unwanted nodes or insert extra nodes, and create a new TOC tree.
import TOCInline from '@theme/TOCInline';
<TOCInline
// Only show h2 and h4 headings
toc={toc.filter((node) => node.level === 2 || node.level === 4)}
minHeadingLevel={2}
// Show h4 headings in addition to the default h2 and h3 headings
maxHeadingLevel={4}
/>
Customizing table of contents generation
The table-of-contents is generated by parsing the Markdown source with a Remark plugin. There are known edge-cases where it generates false-positives and false-negatives.
Markdown headings within hideable areas will still show up in the TOC. For example, headings within Tabs and details will not be excluded.
Non-Markdown headings will not show up in the TOC. This can be used to your advantage to tackle the aforementioned issue.
<details>
<summary>Some details containing headings</summary>
<h2 id="#heading-id">I'm a heading that will not show up in the TOC</h2>
Some content...
</details>
The ability to ergonomically insert extra headings or ignore certain headings is a work-in-progress. If this feature is important to you, please report your use-case in this issue.
Below is just some dummy content to have more table of contents items available on the current page.
Example Section 1
Lorem ipsum
Example Subsection 1 a
Lorem ipsum
Example subsubsection 1 a I
Example subsubsection 1 a II
Example subsubsection 1 a III
Example Subsection 1 b
Lorem ipsum
Example subsubsection 1 b I
Example subsubsection 1 b II
Example subsubsection 1 b III
Example Subsection 1 c
Lorem ipsum
Example subsubsection 1 c I
Example subsubsection 1 c II
Example subsubsection 1 c III
Example Section 2
Lorem ipsum
Example Subsection 2 a
Lorem ipsum
Example subsubsection 2 a I
Example subsubsection 2 a II
Example subsubsection 2 a III
Example Subsection 2 b
Lorem ipsum
Example subsubsection 2 b I
Example subsubsection 2 b II
Example subsubsection 2 b III
Example Subsection 2 c
Lorem ipsum
Example subsubsection 2 c I
Example subsubsection 2 c II
Example subsubsection 2 c III
Example Section 3
Lorem ipsum
Example Subsection 3 a
Lorem ipsum
Example subsubsection 3 a I
Example subsubsection 3 a II
Example subsubsection 3 a III
Example Subsection 3 b
Lorem ipsum
Example subsubsection 3 b I
Example subsubsection 3 b II
Example subsubsection 3 b III
Example Subsection 3 c
Lorem ipsum