A webpage is not always broken because of a large mistake. Small details can produce exactly this problem: debugging: details does not toggle. This guide shows you what to look for, a concrete fix, and how to check that it worked.
The Idea in Plain English
The first summary child serves as the control. Avoid nesting interactive controls inside the summary label.
You can test this using a small local HTML file. Change one part at a time and check the result in the browser before adding more code.
A Working Example
The first part shows a problem. The second part shows a safer or more accurate version. Compare them before reading the explanation.
<!-- Problem -->
<details><p>How it works</p><summary>Open</summary></details>
<!-- Corrected example -->
<details>
<summary>How does it work?</summary>
<p>The browser handles the disclosure.</p>
</details>What Each Part Does
- The details element creates an expandable disclosure.
- A paragraph keeps one idea together as readable text.
- The summary gives a details disclosure its clickable heading.
Before the fix, the browser can behave incorrectly or report a warning. After the change, test the exact failure rather than assuming the page is fixed.
Try It Yourself
Activate the summary with mouse and keyboard and watch the content toggle.
Common Beginner Mistakes
- Check the underlying cause before changing unrelated tags.
- Changing several parts of the example at once, making it difficult to see which part caused a different result.
- Choosing a tag only because its default appearance looks right, without checking whether it describes the content correctly.
Key Takeaways
- The first summary child serves as the control. Avoid nesting interactive controls inside the summary label.
- Before the fix, the browser can behave incorrectly or report a warning. After the change, test the exact failure rather than assuming the page is fixed.
- Test the markup in a browser, and check accessibility and real-world behavior where relevant.