> For the complete documentation index, see [llms.txt](https://avaloniachina.gitbook.io/avalonia/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://avaloniachina.gitbook.io/avalonia/docs/controls/expander.md).

# Expander

The `Expander` control is a control that allows for expanding to show nested content.

### Reference <a href="#reference" id="reference"></a>

[Expander](http://reference.avaloniaui.net/api/Avalonia.Controls/Expander/)

### Source code <a href="#source-code" id="source-code"></a>

[Expander.cs](https://github.com/AvaloniaUI/Avalonia/blob/master/src/Avalonia.Controls/Expander.cs)