HTML & CSS Error Statistics: We Validated the Top 5,000 Websites
- Original researchBetween the Tranco top 5,000 domains, 2,655 served a home page we could read.
- We ran the same validators this site offers for free over every one of them and counted what came back: 100,399 HTML spec violations and 17,599 CSS errors, in 220 distinct message families.
- Published August 11, 2026 · Free to cite with a link.
Unverified
- Original researchBetween the Tranco top 5,000 domains, 2,655 served a home page we could read.
- We ran the same validators this site offers for free over every one of them and counted what came back: 100,399 HTML spec violations and 17,599 CSS errors, in 220 distinct message families.
- Published August 11, 2026 · Free to cite with a link.
Sources: Validatehtml