Detect Dark Mode Preference with JavaScript

By  on  

Seemingly every website, dapp, and app offers a dark mode preference, and thank goodness. Dark mode is especially useful when I'm doing late night coding, or even worse, trading into altcoins. I'm presently working on implementing a dark theme on MetaMask and it got me to thinking: is there a way we can default to dark mode if the user's operating system also defaults to dark mode?

You can determine if the user's operating system prefers dark mode with one quick line of code:

const prefersDarkMode = window.matchMedia("(prefers-color-scheme:dark)").matches; // true

This code snippet takes advantage of the CSS prefers-color-scheme media query with JavaScript's matchMedia API.

From a user experience standpoint, you'll need to be careful in using this snippet. This method is great for setting a default for new users without changing the value for existing users.

Recent Features

Incredible Demos

  • By
    pointer Media Query

    As more devices emerge and differences in device interaction are implemented, the more important good CSS code will become.  In order to write good CSS, we need some indicator about device capabilities.  We've used CSS media queries thus far, with checks for max-width and pixel ratios.

  • By
    MooTools Flashlight Effect

    Another reason that I love Twitter so much is that I'm able to check out what fellow developers think is interesting. Chris Coyier posted about a flashlight effect he found built with jQuery. While I agree with Chris that it's a little corny, it...

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!