File | Settings | Editor | General | Code Folding for Windows and Linux
IntelliJ IDEA | Preferences | Editor | General | Code Folding for macOS
Ctrl+Alt+S images/settings.png

Use this page to specify your code folding preferences.

ItemDescription
Show code folding outline Select this checkbox if you want the code folding toggles (images/foldingMinusStart.png, images/foldingMinusEnd.png and images/foldingPlus.gif) to be shown in the editor. Clear the checkbox to hide the toggles.
Collapse by default Select the code fragments which should be folded by default, that is, when a file is first opened in the editor.

See Also

Procedures:

Getting Started: