<details>
A disclosure widget — expandable content with zero JavaScript.
Baseline: Widely available · Interactive
When to use it
For FAQs, transcripts, advanced options; share a name across several to make a browser-managed exclusive accordion, and open expands by default.
When not to
Don't hide content critical to the page's point inside a closed details; find-in-page may not reveal it everywhere.
Key attributes
open- expanded
name- exclusive accordion group
Example
Do I need an account?
No — every guide is public.
Can I read offline?
Yes — save the page; it is self-contained.
<details name='faq'>
<summary>Do I need an account?</summary>
<p>No — every guide is public.</p>
</details>
<details name='faq'>
<summary>Can I read offline?</summary>
<p>Yes — save the page; it is self-contained.</p>
</details>