Firefox for iOS supports iOS Dark Mode. You can switch between Light Mode and Dark Mode based on any of the following behavior:

• Always match your system settings
• Set automatically based on your screen brightness
• Manually switch it yourself

Automatically match system theme

When you switch your device to light or dark theme, Firefox will match your system theme by default. To change this:

1. Tap the menu button at the bottom of the screen (the menu will be at the top right if you're using an iPad):
   

2. Tap Settings in the menu panel.
3. Tap Theme.
4. Tap the Use System Light/Dark Mode toggle (blue means it’s on).

Manually or automatically set themes

You have the ability to manually or automatically set themes.

1. Tap the menu button at the bottom of the screen (the menu will be at the top right if you're using an iPad):
   

2. Tap Settings in the menu panel.
3. Tap Theme.
4. Tap the Use System Light/Dark Mode toggle to turn it off (gray means it’s off).
5. Tap an option from the Switch Mode menu:
   • Manually: all theme changes will occur manually.

   Tap a theme from the Theme Picker menu:

   • Light
   • Dark

   • Automatically: theme will match your screen brightness.

   Customize your theme’s brightness using the Threshold slider.

You can also enable Night Mode in Firefox for iOS to reduce webpage brightness.