Chat messages might get larger or smaller as Snapchat syncs the text size with the global font size on users’ devices. If users don’t like how their chat messages look, they can change the font size using Control Center on iPhone, or the Font Size settings on Android. To do this on an iPhone, first open the Settings app, tap ‘Control Center’, and hit the + button next to ‘Text Size.‘
Now, open Snapchat and swipe down from the top right corner to open Control Center. Tap the ‘Aa’ button to open the Text Size control, and use the slider to adjust to the preferred size. Select ‘Snapchat Only‘ at the bottom of the screen to apply the change.
Change Snapchat Font Size On Android