Elementor is the more common of the two in our index: it runs on 1,161 websites against 122 for ElementsKit, and 122 sites use both. Counts come from real scans, not vendor claims.
Elementor is a website builder platform for professionals on WordPress.
ElementsKit is an addon for Elementor that adds additional customisation options to the page builder.
122 sites run both Elementor and ElementsKit. That is 100% of the sites using ElementsKit, the smaller of the two.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.