Page Transition Animation (Next.js App Router) Implement page enter/exit transitions in the Next.js App Router , and fix the single most common failure: Framer Motion exit animations never fire on navigation . The reason is structural — in the App Router, when navigating, Next.js unmounts the old route's content and mounts the new one almost immediately. can only animate an exit if the exiting element stays mounted under a persistent wrapper long enough to run the animation. Because the router swaps children out from under it, the exit is skipped. Two approaches solve this: a pathname-keyed w…