Why do you want to change the fonts?

Do you have problems with the fonts?

You can use an extension to set a default font size and page zoom on web pages:

• NoSquint: https://addons.mozilla.org/firefox/addon/nosquint/
• Default FullZoom Level: https://addons.mozilla.org/firefox/addon/default-fullzoom-level/

Hi, okay try this method:

Tools > Options (Fonts & Colors) > Advanced > Untick the box that says 'Allow pages to choose their own fonts, instead of my selection above'.

After that you are able to see your selected fonts appear and if you don't like it just change another to another font via the Fonts & Colors.

That should do it. Cheers!

The problem is that most modern web pages are rather more than just blocks of simple text they have all sorts of formatting and styles.

It is also possible to turn off the styles by using

• view -> page style -> no style,

but I would not recommend it other than as a quick and dirty method of making some pages easier to read or print/copy

The option does not even appear with the Firefox button present; unless you use Alt to temporarily toggle the menubar toolbar on.