<!--
{
  "availability" : [
    "macOS: -"
  ],
  "documentType" : "symbol",
  "framework" : "AppKit",
  "identifier" : "/documentation/AppKit/NSSavePanel/isExtensionHidden",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "AppKit"
    ],
    "preciseIdentifier" : "c:objc(cs)NSSavePanel(py)extensionHidden"
  },
  "title" : "isExtensionHidden"
}
-->

# isExtensionHidden

A Boolean value that indicates whether to display filename extensions.

```
var isExtensionHidden: Bool { get set }
```

## Discussion

When the value of this property is <doc://com.apple.documentation/documentation/Swift/false>, [`NSSavePanel`](/documentation/AppKit/NSSavePanel) shows the filename extension in places where you refer to the file by name. The user can override this value by checking the hide extension menu item, which reflects this value. The default value is <doc://com.apple.documentation/documentation/Swift/true>.

If a user adds or removes a filename extension in the panel’s name field, the panel updates this property to reflect that choice.

> Note:
> Setting this property has no effect if the user has chosen to show all file extensions in Finder.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)