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
    JavaScript Promise API

    While synchronous code is easier to follow and debug, async is generally better for performance and flexibility. Why "hold up the show" when you can trigger numerous requests at once and then handle them when each is ready?  Promises are becoming a big part of the JavaScript world...

  • By
    CSS Gradients

    With CSS border-radius, I showed you how CSS can bridge the gap between design and development by adding rounded corners to elements.  CSS gradients are another step in that direction.  Now that CSS gradients are supported in Internet Explorer 8+, Firefox, Safari, and Chrome...

Incredible Demos

Discussion

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