CSS Clamp Builder
Generate perfect fluid typography with clamp(MIN, PREFERRED, MAX). No math required.
About the CSS Clamp Builder
The CSS Clamp Builder by Grab-Kit is a free online tool designed for frontend developers and web designers. The CSS `clamp()` function is the modern standard for fluid typography, allowing font sizes to scale smoothly between a minimum and maximum size based on the viewport width. However, calculating the mathematical "preferred" value (which requires finding the slope and intercept between your mobile and desktop sizes) is tedious and error-prone. Our tool does the math for you instantly.
Using the tool is incredibly simple. Use the sliders to set your desired minimum font size (for mobile devices) and maximum font size (for desktop screens). You can also adjust the viewport bounds (the screen widths at which the scaling starts and stops). The tool instantly calculates the precise `clamp(MIN, PREFERRED, MAX)` string and displays it in the code box. The live preview box below shows exactly how your text will scale as you resize your browser window. Click "Copy" and paste it directly into your CSS file.
Why use Grab-Kit?
All our tools run entirely in your browser. This means the calculations are performed instantly without any server-side delays. It is completely free, requires no signup, and works flawlessly on both desktop and mobile devices, making it the perfect utility for modern, responsive web development workflows.