About W3.CSS
W3.CSS is a CSS framework developed by the World Wide Web Consortium (W3C), the main international standards organisation for the World Wide Web.
How W3.CSS compares
- #58
CoreUI881 - #59
Aura676 - #60
siimple661 - #61W3.CSS446
- #62
Clarity428 - #63
GOV.UK Toolkit405 - #64GOV.UK Elements228
#61 of 71 UI frameworks we have counts for (of 85) · bars are GitHub stars across these neighbours; the category leader is Flutter at 179k · as of August 22, 2026
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W3.CSS#61 of 71 UI frameworks
siimple#60 of 71 UI frameworks
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How we audit W3.CSS
We measure the detected version against W3.CSS's release history and grade the surrounding stack with a Lighthouse-grade quality audit. Weak or outdated links weigh more - one risky dependency can pull the whole score down.
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Technology definitions from a community-maintained catalogue, licensed GPL-3.0. Attribution and source.