Enter a minimum and maximum size and the viewport range they should scale across, and the tool outputs a clamp() value that grows smoothly between those breakpoints.
clamp(min, preferred, max) locks a value between a minimum and maximum while letting the preferred (often viewport-based) value scale in between.
It gives fluid font sizes that grow with the viewport but never get too small or too large, replacing stacks of media queries.
The tool derives a linear formula in vw plus a rem offset so the size moves proportionally between your chosen viewport widths.