Marcin Wichary:

On her blog, Lea Verou makes a case that each user-facing website dark-mode toggle should only ever show two options, but in a smart way.

The challenge is that any dark mode toggle needs to actually accommodate three options: dark, light, and the default “whatever the system says” (which can be always dark, always light, or change with the time of day). Many toggles simply pass that complexity onto the user:

I have been enjoying the Unsung blog by Marcin Wichary a lot. This post exemplifies why. He takes the smallest ideas in design and UX and dives deep into them.

I have already changed my website’s dark/light mode toggle to work this way! (I never had the tri-state toggle, but any change in preference was only for the current browser tab, it wasn’t getting persisted.)