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

  • By
    Write Better JavaScript with Promises

    You've probably heard the talk around the water cooler about how promises are the future. All of the cool kids are using them, but you don't see what makes them so special. Can't you just use a callback? What's the big deal? In this article, we'll...

  • By
    An Interview with Eric Meyer

    Your early CSS books were instrumental in pushing my love for front end technologies. What was it about CSS that you fell in love with and drove you to write about it? At first blush, it was the simplicity of it as compared to the table-and-spacer...

Incredible Demos

Discussion

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