Below are the step-by-step instructions on how to increase the font size in Firefox
Note: Mac key convention: ' Ctrl ' is used for 'Control', ' Apple ' is used for 'Command' and ' Alt ' is used for the 'Option' key .
Note: For keyboard access make sure ' Full keyboard access ' is turned on - you can turn it on or off; by pressing ' Ctrl ' + ' F1 ' at any time.
Follow these steps to increase or decrease the size of the text for the web page you are viewing:
- Click on the ' View ' menu with the mouse.
- Hover your mouse over ' Text Size ' and choose a different text size from the listed options as shown in Fig 1.
Or to use keyboard shortcuts:
- Press ' Apple ' and ' + ' (plus) to increase the text size and ' Apple ' and ' - ' (minus ) to decrease the text size.
Fig 1
Take the following steps to set a larger text size for all the pages you visit:
- Click the ' Firefox ' menu with the mouse or press ' Ctrl ' + ' F2 ' to highlight the menu bar and then press the right arrow to highlight the ' Firefox ' menu .
- Click on ' Preferences' or press the down arrow to highlight ' Preferences ' and then press ' Enter '.
- Make sure the ' Content ' tab is selected if not click on it (or use the left / right arrow keys to select it).
- Under ' Fonts and Colors ' click on ' Advanced ' or use the ' Tab ' key to highlight it and press the ' Spacebar ' to select - see Fig 2 below.

Fig 2
- Click an the 'Size' drop down menu next to ' Proportional ' and select the font size you want - see Fig 3 below or ' Tab ' to ' Size' and use the up/down arrow keys and the ' Enter ' key to select.

Fig 3
- Click the checkbox ' Allow pages to choose their own fonts, instead of my selections above ' to deselect it (turn it off) or ' Tab ' to the checkbox and press the ' Spacebar ' to deselect it
- Click ' OK ' button or press ' Enter '
- Press ' Apple ' + ' W ' to return to Firefox.
Note: If this does not work it could be because your computer settings cannot be changed due to local IT policies - contact your local IT support for further help.
Top of page 