How to Change Fonts in Mozilla Firefox Reader Mode

Mozilla Firefox definitely wants us to read more online and it aims to make our online reader much more comfortable for us. This is why Mozilla offers something Reader Mode which can be enabled for any webpage to turn that webpage easy for reading. Reader mode strips that webpage off unnecessary and distracting elements. It applies its own easy-on the eyes CSS. The result is a textbook look for the webpages helping is to go through them easily.

When you are reading a webpage using this reading mode, you can click on the fonts icon to select a new font style, font face, font size and the line height. But if you want to change the default font to be used in the reader mode, then you have to do two things – change settings for reader mode and change the default fonts for Firefox.

Firefox Reader Mode Fonts

Here is how you can change the font settings for the Reader mode in the Mozilla Firefox web browser:

  1. Launch Firefox web browser and enter about:config in its address bar. You will have to proceed by clicking on the button labeled “Accept the risk and continue”.
  2. On the advanced settings screen, we search for Reader mode related settings by type reader.font in the search box.
  3. For the reader.font_size setting, we can set a value to make the font size smaller or larger for the reader mode. By default, its value is set to 5. We can change it to 10 to make the fonts larger. Similarly, we can make the fonts smaller by changing it to 2.Firefox Reader Mode Fonts
  4. For the reader.font_type, we can change the value to either serif, sans-serif or monospace. The Serif fonts are those with the sharper edges and Sans-Serif fonts are the rounder ones. The monospace fonts use the same width for all its characters.

For change which font Firefox uses for serif, sans-serif or monospace, we can open the Font settings for Firefox in the following manner:

  1. Launch Firefox and enter about:preferences in the address bar.
  2. Type fonts in the search box. Click on the Advanced button next to the Fonts & Colors.Firefox Reader Mode Fonts
  3. In the small window that opens, you can change the fonts used for serif, sans-serif and monospace. You can also change the font sizes. By default, it uses Arial for Sans-Serif and Times New Roman for Serif.Firefox Reader Mode Fonts

Now whenever you open a webpage using reader mode, it will the newly assigned values as the default. Of course, you can change the values from the Reader mode user interface itself but that requires that you have reader mode opened first. The changes do not reflect in a webpage that was already being viewed using the reader mode. For those already open webpages, you can simply refresh them so that they load the new reader mode font settings.