Next.js is the more common of the two in our index: it runs on 4,683 websites against 2,517 for Next.js App Router, and 2,517 sites use both. Counts come from real scans, not vendor claims.
Next.js is a React framework for developing single page Javascript applications.
The Next.js App Router is a new paradigm for building applications using React's latest features.
2,517 sites run both Next.js and Next.js App Router. That is 100% of the sites using Next.js App Router, 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.