I wrote an article back in 2021 called The Lazy Developer's Dark Mode where I explained how to implement a very basic "dark mode" by using the prefers-color-scheme CSS attribute. This stills works perfectly fine, and in fact there is a cleaner variation of this created by jacksonchen666: These 3 Lines of CSS Will Give You Dark Mode for Free.

But today I wanted to show how to add dark mode functionality to a website without any CSS at all.

<meta name="color-scheme" content="dark light">

Add that line inside the head tags on your HTML files and you're good to go.

Minor Caveat

I mentioned this same issue on the official barf blog post but it doesn't hurt to repeat it here. Safari still has minor ahref / link color issue when defaulting to browser dark mode. If supporting that browser is a deal-breaker for you, I suggest looking at my hacky solution.

Hopefully this helps others to add dark mode to their existing websites and projects with minimal effort!