How to Change Font Size on HTC One? It is very easy, you have four options: Small, Medium, Large, Extra Large. To change the Font size on HTC One do as follows:
Note that, this option changes the font size in all over the phone; from menus to text messages.
1. Open “Settings” app
2. Tap “Display, gestures & buttons”
3. Tap “Font Size”
4. Select Small, Medium, Large, Extra large