---
title: contentType
framework: quicklookthumbnailing
role: symbol
role_heading: Instance Property
path: quicklookthumbnailing/qlthumbnailgenerator/request/contenttype
---

# contentType

The content type of the source data for the thumbnail request.

## Declaration

```swift
var contentType: UTType! { get set }
```

## Discussion

Discussion Quick Look Thumbnailing uses the content type of the source data to determine the provider of the thumbnail and the icon styles it applies when you request iconMode. If you don’t set this property, Quick Look Thumbnailing derives the content from the file extension. When the file doesn’t have a meaningful extension and you know the content type, set the property directly.

## See Also

### Describing the Requested Thumbnail

- [size](quicklookthumbnailing/qlthumbnailgenerator/request/size.md)
- [scale](quicklookthumbnailing/qlthumbnailgenerator/request/scale.md)
- [representationTypes](quicklookthumbnailing/qlthumbnailgenerator/request/representationtypes-swift.property.md)
- [minimumDimension](quicklookthumbnailing/qlthumbnailgenerator/request/minimumdimension.md)
- [iconMode](quicklookthumbnailing/qlthumbnailgenerator/request/iconmode.md)
- [QLThumbnailGenerator.Request.RepresentationTypes](quicklookthumbnailing/qlthumbnailgenerator/request/representationtypes-swift.struct.md)