To change the font size in Safari Browser
If you just want to change on each page the font size to fit in the Browser with the key combination [Cmd] & [ + ]. Reduce the size of the font using [Cmd] & [-]. The next steps explain how to change permanently the font size for all pages.
- You Open Safari.
- Navigate in the menu bar "Safari" to the "settings ..." and open the "Advanced"tab.
- Under the menu item "accessibility" in "No font sizes smaller than" a hook. (see Screenshot)
- Then choose a font size that you want to allow at a minimum. To do this, tap on the drop-down menu next to the Option from step 3 and enter any positive number. You can close the menu.
- Note that some web sites are tailored to specific font sizes and thus, display errors can occur.

Font size in Safari to change
Practice, the tip describes a solution for Mac OS X 10.10 and Safari Version 8.0 on a MacBook Air. Another article explains how to in Safari, a window open in full screen.