Increase the String pref layout.css.devPixelsPerPx from 1.0 to 2.0 in 0.1 or 0.05 steps to adjust the size of all fonts and other elements in Firefox. In current Firefox versions this pref is a String value parsed to a float and allows to fine tune the dimensions of all elements (user interface and web pages) more precisely. To open the <i>about:config</i> page, type <b>about:config</b> in the location (address) bar and press the "<i>Enter</i>" key, just like you type the url of a website to open a website.<br /> If you see a warning then you can confirm that you want to access that page.<br /> *Use the Filter bar at to top of the about:config page to locate a preference more easily. *Preferences that have been modified show as bold(user set). *Preferences can be reset to the default or changed via the right-click context menu. ---- You can use an extension to set a default font size and page zoom on web pages: *Default FullZoom Level: https://addons.mozilla.org/firefox/addon/default-fullzoom-level/ *NoSquint: https://addons.mozilla.org/firefox/addon/nosquint/

I used the config method and it worked brilliantly! You are a super-legend! Many thanks : )