This section explains how to change the fonts used in the Firefox browser for macOS 12 Monterey. This is a step-by-step guide with pictures of the screens to help.
1. Click the Menu button in the top-right corner of the Firefox window and select Settings from the menu.
2. Scroll down to the Language and Appearance section and click the Advanced button under Fonts and Colours.
3. You can now choose which fonts Firefox will use for the Serif, Sans Serif and Monospace font styles, using the drop-down menu for each. You can also apply a default Size to each font.
4. Many modern websites have fonts that are set by the designer and can’t usually be changed, but if you click and untick the box labelled Allow pages to choose their own fonts, instead of your selections above, your new fonts will override these. When you’re happy with your selections, click OK.
Note: If this does not work it could be because your computer settings are managed by someone else (an IT department or administrator for example). If so, you will need to contact them to access these settings or for help.