HTML Table of Contents for Documentation Sites

A table of contents is a list of internal links to sections of a page. Its order should follow the headings people will read. The important question is always where the link leads and whether the person reading the page can predict it.

What You Need to Know

Use an ordered list when the sequence matters. Do not invent links to sections that do not exist in the document.

Links are the pathways through a website. The words on a link should help someone choose where to go before clicking it.

Example: See It in Action

This example keeps the idea small. Copy it carefully, then follow the explanation instead of guessing what the browser will do.

This is a short HTML fragment. To try it as a webpage, put it inside the body element of a complete HTML document.

<nav aria-label="Contents">
    <ol>
        <li><a href="#overview">Overview</a>
        </li>
        <li><a href="#steps">Steps</a>
        </li>
    </ol>
</nav>
<h2 id="overview">Overview</h2>
<h2 id="steps">Steps</h2>

Let’s Understand the Example

• An a element becomes a working link when it has an href. Its visible text should tell readers where they will go.
• Nav identifies a major collection of navigation links.
• Ol groups items whose order or numbering matters.
• Aria-label supplies an accessible name when a visible label is unavailable or inadequate.
• Href contains the destination of a link. A value starting with # points to an id on the same page.
• Id gives one element a unique name within the page, so a link, label, or script can point to it.

The first example link points to #overview. Check whether that destination exists relative to the document. A link changes where readers go; it does not perform an action such as saving a form.

What Should You See?

You should see a link named “Overview”. Selecting it leads to #overview when that destination exists. Try it with the mouse and the keyboard.

Imagine this link is read out of context. Would its text still explain the destination? Rename unclear links before trying to make them look nicer with CSS.

Try It Yourself

1. Add a section and connect it with a matching fragment link.
2. Save your changes, open or refresh the page, and compare the result with the original example.
3. Tell a friend what your change did. If you are not sure, undo it, refresh the page, and compare.

Common Beginner Mistakes

• Letting an article's headings change while leaving the contents links outdated.
• Avoid dead links, empty href values and clickable-looking text without a real destination.

Key Takeaways

• A table of contents is a list of internal links to sections of a page.
• An a element becomes a working link when it has an href. Its visible text should tell readers where they will go.
• Use an ordered list when the sequence matters. Do not invent links to sections that do not exist in the document.