Fast Simon vs Klevu

Klevu is used by more websites in our catalog: 287 use Fast Simon and 386 use Klevu.

Klevu sites have the higher median Ahrefs Domain Rating (Fast Simon: 14, Klevu: 39).

Between 2026-06 and 2026-07, Fast Simon went from 0.01% to 0.03% of all tracked sites, while Klevu went from 0.06% to 0.04%. Fast Simon is gaining ground faster in our index.

0 websites in our catalog use both Fast Simon and Klevu.

Adoption is counted from Site Stats Database's own crawl; Domain Rating comes from Ahrefs and traffic from DataForSEO. Figures reflect the sites we track and refresh at least monthly.