ISR / SWR Payload Extraction

What's new#

Payload extraction now works with ISR (incremental static regeneration), SWR (stale-while-revalidate), and cache route rules. Previously only fully pre-rendered pages produced _payload.json files.

Why you'd care#

A payload file is the page's data, serialized. When it exists, client-side navigation to that page reuses the cached data instead of hitting your API again. Before 4.3, ISR/SWR pages couldn't do this — every navigation re-fetched. Now they can, and CDNs (Vercel, Netlify, Cloudflare) can cache the payload right next to the HTML.

Before#

An ISR product page revalidated its HTML on a schedule, but client navigation still fired fresh API calls for the data:

export default defineNuxtConfig({
  routeRules: {
    '/products/**': { isr: 3600 }
  }
})

HTML: cached. Data on client nav: re-fetched every time.

After#

Same config — but now Nuxt also emits a cached _payload.json:

export default defineNuxtConfig({
  routeRules: {
    '/products/**': {
      isr: 3600 // revalidate hourly; payload cached alongside
    }
  }
})

Client navigation to /products/123 can now serve data straight from the cached payload — fewer API calls, faster transitions.

Do it yourself#

1. Add an isr route rule for a data-driven section, e.g. '/products/**': { isr: 3600 }.
2. In that page, load data with useAsyncData / useFetch as normal.
3. Build and preview the app (nuxt build then nuxt preview).
4. Navigate to a product page, then use client-side links to move between products.
5. Watch the network tab — data should come from the cached payload, not repeated API calls.

Gotchas#

• This is a production/caching behavior. You won't see the full effect with a plain nuxt dev server unless payload extraction in dev is enabled (that's the next step).
• Payloads are only as fresh as your ISR/SWR window — pick a revalidation interval that matches how often the data actually changes.

Recap#

Caching route rules now extract payloads too, so cached pages stop re-fetching their data on client navigation. Turn it on wherever you already use isr, swr, or cache.