Dark mode: preference or default?

In a few years dark mode went from a developer setting to something the operating system simply passes along. Your visitor does not choose it on your site: it went on at night on their phone, and everything else is expected to follow. So the question is not whether you offer it, but whether your site looks broken to someone who already has it on. It usually breaks on one thing — artwork with a white background, sitting in a dark page like a lamp in your face. And a good dark mode is not your colours inverted: pure white text on pure black reads worse than the light version you already had.

Where it goes wrong

• Logos and illustrations with a white background baked in
• Shadows that stop creating depth in the dark
• Brand colours that lose contrast on a dark surface
• Forms whose input fields disappear
• Emails and PDFs that never make the switch

Building it properly is design-system work rather than styling: every colour gets a counterpart, every image a variant or a transparent background. That is a day up front and a standing agreement afterwards.

Where we start

First make sure nothing breaks when the system is set to dark. Full support after that depends on your audience: for a software product or a developer tool it is expected, for a restaurant site nobody asks.