The desired width of the output image.

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

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

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



value may be one of:

  • Absolute width: An integer between 1 and 8192.
  • Relative width: 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 width relative to the image's natural width.


  1. The maximum output dimensions are 8,192 x 8,192 pixels.
  2. If the image is animated, the maximum output dimensions apply to the sum of the area of all the frames of the image. For example, a 1024x1024px GIF could have 64 frames before it would exceed the size limit.
  3. Because we use a positive number less than 1 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, width=250p would return an image that is 250% the width of the original. We use p as a simple way to represent percent.
  4. If the requested width is a fraction of a pixel (e.g., as a result of applying a percentage value for width), it is rounded to the nearest integer.


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

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