v150 · DOM · Forms
Sync Inspector
This inspector attaches MutationObserver instances to three real <selectedcontent> descendants. Change the selection to see when each native mirror receives the selected option clone.
Checking selectedcontent / customizable select support…
Chrome 150 updates every descendant
<selectedcontent>. The first mirror lives in the select button; mirrors B and C are extra descendants in the same select subtree.
Customizable select with observed selectedcontent mirrors
0selections made
0times all 3 contained clone text
// Change the select to see native selectedcontent observer records…
how it works
<select>
<button>
<selectedcontent></selectedcontent> <!-- Mirror A -->
<selectedcontent></selectedcontent> <!-- Mirror B -->
<selectedcontent></selectedcontent> <!-- Mirror C -->
</button>
<option>Option 1</option>
<option>Option 2</option>
</select>see also
- Multiple Mirrors — three mirrors at different DOM positions
- Mutation Timing — deferred clone during DOM mutations
- Styled Mirrors — different visual representations per mirror
- ChromeStatus entry
implementation reference
Need the exact API surface, compatibility boundaries, errors, lifecycle, and source links? Read the matching gendn reference ↗