Below are the step-by-step instructions on how to increase the font size in Mozilla Firefox.

Instructions

1. Open the ' Tools ' menu with the mouse or press ' Alt ' + ' T ' .
2. Select the ' Text Size ' option with the mouse or by pressing ' S ' twice.
3. Increase or decrease the text size with the mouse or by using the up and down arrow keys and pressing ' Enter '.
4. Alternatively you can press ' Ctrl ' and ' + ' to increase the text size, ' Ctrl ' and ' - ' to decrease the text size. ' Ctrl ' and ' 0 ' returns you to the default size.

Follow these steps to set a minimum text size for all pages you visit:

1. Click on the ' Tools ' menu with the mouse or press ' Alt '+' T ' .
2. Make sure that the ' General ' option is selected - if not either click on it or press ' Tab ' until it is highlighted (in blue) and then press the ' Enter ' key.
3. Click on ' Fonts & Colors ' , or press ' F ' , to open the ' Fonts and Colors ' dialog box (see Fig 1 below).
4. Click on ' Minimum font size ' box or press ' Alt '+' Z ' . Use the up and down arrows to select a new font size and press ' Enter '.
5. Click on ' Always use my:' 'Fonts ' checkbox, or tab to this checkbox and press the ' Spacebar '.
6. Click ' OK ' button or tab to ' OK ' button and press ' Enter ' .