Elementor is the more common of the two in our index: it runs on 1,242 websites against 6 for Newspack. Counts come from real scans, not vendor claims.
Elementor is a website builder platform for professionals on WordPress.
Newspack is an open-source publishing platform built on WordPress for small to medium sized news organizations. It is an “opinionated” platform that stakes out clear, best-practice positions on technology, design, and business practice for news publishers.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.