Ask three people what Cache-Control a Next.js page sends and you'll get three answers. All three can be right. It depends on how the page is rendered, which router you use, and whether Vercel sits in front of it.

I ran a live check on nextjs.org today to have something concrete to look at. Here's how to read what came back, and what changes when you host Next.js yourself.

The baseline: two requests to nextjs.org

The homepage HTML (trimmed to the caching-related headers):

cache-control: public, max-age=0, must-revalidate x-vercel-cache: HIT age: 572 x-nextjs-prerender: 1 x-nextjs-stale-time: 300 vary: rsc, next-router-state-tree, next-router-prefetch, next-router-segment-prefetch

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A JavaScript chunk from the same page:

cache-control: public,max-age=31536000,immutable x-vercel-cache: HIT age: 48724 etag: W/"_next/static/immutable/chunks/3-f__u1tgqe9w.js"

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These two responses cover most of what you need to know.

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