UtilTools

CSS Clamp / Fluid Size Generator

Fluid typography that scales between two viewports.

CSS Clamp Generator produces a clamp() expression that scales a size smoothly between a minimum and a maximum across a viewport range — fluid typography and spacing without media queries. It shows the resulting curve, and warns when a value would break zoom accessibility.

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Runs entirely on your device. No file or text you enter here is uploaded. How to verify it.

How to use CSS Clamp / Fluid Size Generator

  1. Set the minimum and maximum size and the viewport range.
  2. Read the generated clamp() expression.
  3. Check the curve and copy the CSS.

Questions about CSS Clamp / Fluid Size Generator

How does clamp() produce fluid sizing?
The middle argument is a linear function of the viewport width written in vw plus a rem offset. Clamp bounds it at the minimum and maximum, so the size grows with the viewport and then stops.
Why does the preferred value use rem as well as vw?
A pure vw value ignores the user's browser font size setting, which breaks zoom and fails WCAG 1.4.4. Mixing in a rem term keeps the text responsive to both the viewport and the user's preference.
Can I use it for spacing too?
Yes, and it is arguably more useful there — fluid padding and gaps remove a whole class of breakpoint fiddling.
What viewport range should I set?
320px to 1280px is the common choice: the narrowest phone worth supporting up to a typical laptop. Past the maximum the size stops growing, so wide monitors get the maximum value, which is usually what you want for line length. The table below the curve shows the computed size from 320px to 1920px so you can sanity-check both ends.
Which browsers support clamp()?
Every current one. Chrome, Edge and Firefox have supported clamp() since 2020, Safari since 13.4; Internet Explorer never will. For a fallback, put a plain declaration on the line before — browsers that cannot parse the clamp value discard it and keep the earlier one.
Is CSS Clamp / Fluid Size Generator really free, with no limits?
Yes. There is no account, no daily cap, no file-size tier and no watermark, because there is no server cost to recover. The site is funded by clearly disclosed partner recommendations on the Partners page, never by metering the tools.
Are my files or text uploaded when I use CSS Clamp / Fluid Size Generator?
No. Everything is processed by JavaScript running in your browser, on your device. You can verify it: open your browser's developer tools, switch to the Network tab, and use the tool. You will see no request carrying your data — because there is nowhere for it to go.