---
title: kCGWindowAlpha
framework: coregraphics
role: symbol
role_heading: Global Variable
path: coregraphics/kcgwindowalpha
---

# kCGWindowAlpha

## Declaration

```swift
let kCGWindowAlpha: CFString
```

## Discussion

Discussion The value for this key is a CFNumber type (encoded as CFNumberType.floatType) that contains the window’s alpha fade level. This number is in the range 0.0 to 1.0, where 0.0 is fully transparent and 1.0 is fully opaque.

## See Also

### Constants

- [conversionBlackPointCompensation](coregraphics/cgcolor/conversionblackpointcompensation.md)
- [kCGDisplayBitsPerPixel](coregraphics/kcgdisplaybitsperpixel.md)
- [kCGDisplayBitsPerSample](coregraphics/kcgdisplaybitspersample.md)
- [kCGDisplayBlendNormal](coregraphics/kcgdisplayblendnormal.md)
- [kCGDisplayBlendSolidColor](coregraphics/kcgdisplayblendsolidcolor.md)
- [kCGDisplayBytesPerRow](coregraphics/kcgdisplaybytesperrow.md)
- [kCGDisplayFadeReservationInvalidToken](coregraphics/kcgdisplayfadereservationinvalidtoken.md)
- [kCGDisplayHeight](coregraphics/kcgdisplayheight.md)
- [kCGDisplayIOFlags](coregraphics/kcgdisplayioflags.md)
- [kCGDisplayMode](coregraphics/kcgdisplaymode.md)
- [kCGDisplayModeIsInterlaced](coregraphics/kcgdisplaymodeisinterlaced.md)
- [kCGDisplayModeIsSafeForHardware](coregraphics/kcgdisplaymodeissafeforhardware.md)
- [kCGDisplayModeIsStretched](coregraphics/kcgdisplaymodeisstretched.md)
- [kCGDisplayModeIsTelevisionOutput](coregraphics/kcgdisplaymodeistelevisionoutput.md)
- [kCGDisplayModeUsableForDesktopGUI](coregraphics/kcgdisplaymodeusablefordesktopgui.md)