MZSoft Studio
How to Get Dark Mode on Every Website in Safari (iPhone, iPad and Mac)
TL;DR
Install Owl, switch it on in Safari's extension settings, and choose "Allow on Every Website". Owl then rewrites each page's colours before it paints, so there is no flash of white.
iPhone and iPad
Settings ▸ Apps ▸ Safari ▸ Extensions ▸ Owl. Turn it on and allow it on every website.
Mac
Safari ▸ Settings ▸ Extensions ▸ Owl. Enable it and allow every website.
Use it
Open a site. It’s dark before it paints. Use the toolbar button to restore a site that looks better light.
If a site looks off
Switch to the plain dark stylesheet fallback for that page.
FAQ
Why “Allow on Every Website”? Owl has to be allowed on a site to darken it. Allowing every website is what keeps it working as you browse.
One purchase for all devices? Yes: iPhone, iPad and Mac.