The HTMLImageElement interface's read-only naturalWidth property returns the intrinsic (natural), density-corrected width of the image in CSS pixels.
This is the width the image is if drawn with nothing constraining its width; if you neither specify a width for the image nor place the image inside a container that limits or expressly specifies the image width, this is the number of CSS pixels wide the image will be.
The corresponding naturalHeight method returns the natural height of the image.
Note: Most of the time the natural width is the actual width of the image sent by the server. Nevertheless, browsers can modify an image before pushing it to the renderer. For example, Chrome degrades the resolution of images on low-end devices. In such cases, naturalWidth will consider the width of the image modified by such browser interventions as the natural width, and returns this value.