https://thenextweb.com/apps/2020/02/25/whatsapp-dark-mode-web-desktop/

WhatsApp wants you to have a consistent experience across platforms — so it’s bringing dark mode to desktop.

The Facebook-owned messenger appears to be working on a dark theme for the Web version of its app, serial WhatsApp leaker WABetaInfo has noticed. The current implementation is pretty rough around the ages from the looks of it, though, so it might take some time to smooth out the kinks.