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.
Syntax
let naturalWidth = htmlImageElement.naturalWidth;
Value
An integer value indicating the intrinsic width of the image, in CSS pixels. This is
the width at which the image is naturally drawn when no constraint or specific value is
established for the image. This natural width is corrected for the pixel density of the
device on which it's being presented, unlike the value of
width
.
If the intrinsic width is not available—either because the image does not specify an
intrinsic width or because the image data is not available in order to obtain this
information, naturalWidth
returns 0.
Example
This example displays both the natural, density-adjusted size of an image as well as its rendered size as altered by the page's CSS and other factors.
HTML
<div class="box">
<img src="/files/16797/clock-demo-400px.png" class="image">
</div>
<div class="output">
</div>
The HTML features a 400x398 pixel image which is placed inside a
<div>
.
CSS
.box {
width: 200px;
height: 200px;
}
.image {
width: 100%;
}
.output {
padding-top: 2em;
}
The main thing of note in the CSS above is that the style used for the container the image will be drawn in is 200px wide, and the image will be drawn to fill its width (100%).
JavaScript
let output = document.querySelector(".output");
let image = document.querySelector("img");
window.addEventListener("load", event => {
output.innerHTML += `Natural size: ${image.naturalWidth} x ` +
`${image.naturalHeight} pixels<br>`;
output.innerHTML += `Displayed size: ${image.width} x ` +
`${image.height} pixels`;
});
The JavaScript code dumps the natural and as-displayed sizes into the
<div>
with the class output
. This is done in response to
the window's load
event handler, in order to ensure
that the image is available before attempting to examine its width and height.
Result
Specifications
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'HTMLImageElement.naturalWidth' in that specification. |
Living Standard |
Browser compatibility
BCD tables only load in the browser