glimm

glimm is a React and Next.js library that sweeps a single WebGL band across the screen during route changes, revealing the new page underneath it. It weighs under 10 KB with no runtime dependencies, builds its one WebGL context only on the first transition, and offers three triggers: a link component, a router hook, or an interceptor for every internal link. Six cosine-gradient palettes and ten easing curves set the mood, and both the band width and the palette can be customised.