Enable dark mode for Chrome on macOS
1. Open 'System Preferences', click 'General', select 'Appearance'.
2. Select the 'Dark' option. As with Windows, all apps with a native dark mode will change automatically with no further input from you.
Enable dark mode for Chrome on Android
1. To activate it, enter chrome://flags in the browser's address bar.
2. Tap the 'Search flags' box and enter the work dark. You'll find two options here: 'Android web contents dark mode' and 'Android Chrome UI dark mode'. If you activate the first option, Chrome will detect if a site's developers have created a dark version and select it automatically.. .
^^ continued
If there's no dark version available, the browser will invert the site's colors. Activating the second option means that the browser interface itself will turn dark
3. Tap the drop-down menu under each of these options and change the setting to 'Activated', then restart Chrome.
4. Now open the settings menu, tap 'Themes' and select 'Dark'. If you can't see the Themes option, restart Chrome again and it should appear
Enable dark mode for Chrome on iOS
(iOS is trickier and it should be available to all in the next chrome update)
For the time being, you can use the Invert feature to achieve a similar effect.
1. Open 'Settings' and select 'General > Accessibility > Display accomodations'.
2. Toggle 'Classic Invert' to invert the colors of everything on your device's screen, or 'Smart invert' to leave images alone but invert everything else.