If you want to increase the font in everything then do this: * Menu app icon > Options/Preferences > General * Scroll down to the very bottom * click on 'Config Editor' button to open 'about:config' * Accept the risk. * In search type: '''pixels''' * Look for this line: '''layout.css.devPixelsPerPx''' * Double left click on that line to open the 'Enter string Value' box so you can edit the Value. The default value will be a negative number: ''' -1.0''' * Enter a new positive number eg: 1.25 or 1.5 or 2.0 or 2.2 * click on OK the effect is immediate, so you can modify that number until it looks ok for you. Image below as guide.