You can try the following Add-on - https://addons.mozilla.org/en-US/firefox/addon/theme-font-size-changer/ Also see - *http://kb.mozillazine.org/Accessibility_features_of_Firefox *http://www.accessfirefox.org/

The font size is also changed if you adjust the DPI preference. This may need to be created, if it does not exist. The default value will be -1 enter figures between 1 and 2 to start off e.g. 1.5 This is not an option to try if an add on will do this for you. * http://www.accessfirefox.org/Theme-Font-Size-Changer.php ------------- If you are interested though See * http://kb.mozillazine.org/Layout.css.dpi * http://kb.mozillazine.org/About:config Follow these steps # Type in ''about:config'' in the location bar and click the arrow # accept any warning # key into the search filter ''dpi'' that narrows down the listing,probably only the single preference '''''layout.css.dpi '''''will show # if the preference does not exist create it use New -> string from right click # right click the preference and set the value ( Oddly this is not working at the moment on my Ubuntu Aurora install. The last time [https://bugzilla.mozilla.org/show_bug.cgi?id=644952 I] modified this pref would have been on a Windows Firefox 5 install. _{Possibly a bug[https://bugzilla.mozilla.org/show_bug.cgi?id=798362 798362] is involved IF so some add-ons may have problems} )

Thanks so much for the replies. I will give them a try. This was just the trick! [https://addons.mozilla.org/en-US/firefox/addon/theme-font-size-changer/]