You can make text responsive in Bootstrap by using vw
units or media queries.
The text size can be set with a vw
unit, which means the "viewport width".
Viewport is the browser window size. 1vw = 1% of viewport width. If the viewport is 50cm wide, 1vw is 0.5cm.
Resize the browser window to see how the font size scales.
<h1 style="font-size: 8vw;">I am responsive</h1>