Next.js(5)
The App Router, route handlers and server components, and where Next.js stops behaving like plain React.
- Next.js App Router Navigation, Measured: What a Link Prefetches and Which next/router APIs Are GoneWe measured client-side navigation on a deployed Next.js 16.1 site: a soft navigation transfers about half the bytes of a full page load, and a <Link> prefetch transfers the same payload as the navigation it prepares - the whole route, once per link in the viewport, in production. Then we read the useRouter return type out of the installed package: six methods, and no router.events, router.query, router.pathname, router.isReady, router.beforePopState or shallow routing.19 min read
- What a Next.js Route Handler Does When It Throws: 13 Cases, Measured in Dev and ProductionWe seeded thirteen failure modes into Next.js 16.1 route handlers and recorded the status, headers and body the client got back, under next dev and under a production build. An uncaught throw is an empty 500 with no Content-Type. Throwing a Response does not set its status. A stream that fails after its first byte is a truncated 200. Dev and production returned the same thing every time.15 min read
- Testing Next.js Route Handlers: Ten Seeded Bugs, Four Methods, and What Each One MissedWe put ten defects into real route handlers and ran four testing methods at them: a direct call, next-test-api-route-handler, next start, and the Cloudflare Workers build we deploy. Two methods pass a handler that is broken, and one fails a handler that is fine.18 min read
- Next.js API Routes: Route Handlers, Caching, and the Server Actions DecisionHow route handlers actually behave in Next.js 16: GET is no longer cached by default, params are async, and most of what you need is a server action instead. With a real deployment that is not on Vercel.17 min read
- Next.js 16 App Router: Getting Started, and What the Model CostsThe App Router explained through a site that actually runs on it: server components, async request APIs, generateStaticParams, and the three things that break when you deploy somewhere other than Vercel.13 min read