The desired height of the output image.

The height parameter enables dynamic height resizing based on pixels and percent values.

The {value} can be either a positive integer or a positive number less than 1. If the value is an integer greater than or equal to 1, the value is interpreted as a pixel height. If the height parameter is less than 1, the value is interpreted as a percentage height.

Unless a width parameter is present, the height value will cause the width of the image to be scaled in proportion to the requested height. If both width and height are omitted, the input image dimensions are used.



value may be one of:

  • Absolute height: An integer number of pixels.
  • Relative height: A fraction between 0 and 0.99 (e.g., 0.5) or a percentage between 0 and 100 followed by the letter p (e.g., 50p). In either case, the value indicates the desired height relative to the image's natural height.


  1. The maximum output dimensions are 8,192 x 8,192 pixels.
  2. Because we use a positive number between 0 and 0.99 to return a percentage-based scaled image, in order to return an image that is 100% or more, a p suffix can be appended to the value. For example, height=250p would return an image that is 250% the height of the original. We use p as a simple way to represent percentages.
  3. If the requested height is not a whole number of pixels (e.g., as a result of applying a percentage value for height), it is rounded to the nearest integer.


Click the links to view the transformed image using a demo Fastly IO service.

Example usageDescription
?height=200Resize the height to 200px
?height=0.10Resize the height to 10% of the input image
?height=150pResize the height to 150% of the input image
?height=200&width=0.50Force resize to a height of 200px and a width that is 50% of the original
?height=150&width=150&fit=boundsFit image within a 150 x 150px rectangle
?height=200&dpr=2Resize the height to 400px (200 CSS pixels for screens with a device pixel ratio of 2)