Samsung
Change Text Size in Samsung Internet Browser auf Samsung
Website text size is normally set by the page itself, not by your phone. That is why the same article can look tiny on one site and oversized on another, even though your system font settings did not change.
Samsung Internet includes its own scaling option that sits on top of whatever a page defines. It lets you shrink or enlarge all browser text by a percentage, independent of the website's own styling.
To change it, open Tap on Internet ➔ Open the Menu ➔ Tap on Text size. A slider appears where you can Swipe left or right to adjust the Text size between 50 and 200 percent. Confirm with Tap on OK to apply the change immediately.
A value of 100 percent keeps the page's original sizing. Lower values shrink dense text-heavy pages so more content fits on screen, while higher values help on pages with small fixed fonts that ignore zoom gestures.
This setting only affects Samsung Internet. If text also looks wrong in other apps or on your home screen, the issue sits in the system-wide font size under your phone's display or accessibility settings instead, not in the browser.