---
title: width
summary: null
url: https://www.fastly.com/documentation/reference/io/width
---

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`](https://www.fastly.com/documentation/reference/io/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.

## Syntax

```text
width={value}
```

`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.

## Notes

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.

## Examples

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

| Example usage                                                                                         | Description                                                                                                                                          |
| ----------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
| [`?width=200`](https://www.fastly.io/image.jpg?width=200)                                             | Resize the width to 200px                                                                                                                            |
| [`?width=0.10`](https://www.fastly.io/image.jpg?width=0.10)                                           | Resize the width to 10% of the input image                                                                                                           |
| [`?width=150p`](https://www.fastly.io/image.jpg?width=0.10)                                           | Resize the width to 150% of the input image                                                                                                          |
| [`?width=200&height=0.50`](https://www.fastly.io/image.jpg?width=200&height=0.50)                     | Force resize to a width of 200px and a height that is 50% of the original.                                                                           |
| [`?width=150&height=150&fit=bounds`](https://www.fastly.io/image.jpg?width=150&height=150&fit=bounds) | Fit image within a 150 x 150px rectangle                                                                                                             |
| [`?width=200&dpr=2`](https://www.fastly.io/image.jpg?width=200&dpr=2)                                 | Resize the width to 400px (200 [CSS pixels](https://developer.mozilla.org/en-US/docs/Glossary/CSS_pixel) for screens with a device pixel ratio of 2) |