How to Display Mode-Specific Images

Now that we have most of the basics of HTML and CSS in the browser, we’ve begun implementing new features that I would consider “quality of life” improvements, many of which have been inspired by mobile. One great example is the CSS prefers-color-scheme media query, which allows developers to cater their design to system theme (dark or light) preference:

/* Light mode */
@media (prefers-color-scheme: light) {
    html {
        background: white;
        color: black;
    }
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
    html {
        background: black;
        color: white;
    }
}

While watching my Twitter feed fly by, I saw an awesome trick from Flavio Copes:

<picture>
    <source
        srcset="dark-logo.png"
        media="(prefers-color-scheme: dark)">
    <img src="http://davidwalsh.name/logo.png" />
</picture>

By applying the media query to the source, you can define the image to load. This technique is obviously valuable when you need to load a new source image and not simply change a CSS property.

Maybe not the most maintainable code but very clever nonetheless!