HTMLImageElement: naturalHeight property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The HTMLImageElement interface's naturalHeight property is a read-only value which returns the intrinsic (natural), density-corrected height of the image in CSS pixels.

This is the height the image is if drawn with nothing constraining its height; if you don't specify a height for the image, or place the image inside a container that either limits or expressly specifies the image height, it will be rendered this tall.

Note: Most of the time the natural height is the actual height 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, naturalHeight will consider the height of the image modified by such browser interventions as the natural height, and returns this value.

Value

An integer value indicating the intrinsic height, in CSS pixels, of the image. This is the height at which the image is naturally drawn when no constraint or specific value is established for the image. This natural height is corrected for the pixel density of the device on which it's being presented, unlike height.

If the intrinsic height is not available—either because the image does not specify an intrinsic height or because the image data is not available in order to obtain this information, naturalHeight returns 0.

Examples

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

html
<div class="box">
  <img
    src="/https/developer.mozilla.org/en-US/docs/Web/HTML/Element/img/clock-demo-400px.png"
    class="image"
    alt="A round wall clock with a white dial and black numbers" />
</div>
<pre></pre>

The HTML features a 400x398 pixel image which is placed inside a <div>.

CSS

css
.box {
  width: 200px;
  height: 200px;
}

.image {
  width: 100%;
}

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

js
const output = document.querySelector("pre");
const image = document.querySelector("img");

image.addEventListener("load", (event) => {
  const { naturalWidth, naturalHeight, width, height } = image;
  output.textContent = `
Natural size: ${naturalWidth} x ${naturalHeight} pixels
Displayed size: ${width} x ${height} pixels
`;
});

The JavaScript code dumps the natural and as-displayed sizes into the <pre>. This is done in response to the images's load event handler, in order to ensure that the image is available before attempting to examine its width and height.

Result

Specifications

Specification
HTML Standard
# dom-img-naturalheight-dev

Browser compatibility

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