What is Incremental Static Regeneration (ISR)?

Q: What is Incremental Static Regeneration (ISR)?

Update static content without rebuilding the entire site Reduce server load by serving prerendered, static pages for most requests Ensure proper cache-control headers are automatically added to pages Handle large amounts of content pages without long next build times interface Post { id: string title: string content: string } // Next.js will invalidate the cache when a // request comes in, at most once every 60 seconds. export const revalidate = 60 // We'll prerender only the params from `generateStaticParams` at build time. // If a request comes in for a path that hasn't been generated, // Next.js will server-render the page on-demand. export const dynamicParams = true // or false, to 404 on unknown paths export async function generateStaticParams() { const posts: Post[] = await fetch('https://api.vercel.app/blog').then((res) => res.json() ) return posts.map((post) => ({ id: String(post.id), })) } export default async function Page({ params, }: { params: Promise }) { const { id } = await params const post: Post = await fetch(`https://api.vercel.app/blog/${id}`, {next: { revalidate: 3600 }}) .then((res) => res.json()) return ( {post.title} {post.content} ) } During next build, all known blog posts are generated (there are 25 in this example) All requests made to these pages (e.g. /blog/1) are cached and instantaneous After 60 seconds has passed, the next request will still show the cached (stale) page The cache is invalidated and a new version of the page begins generating in the background Once generated successfully, Next.js will display and cache the updated page If /blog/26 is requested, Next.js will generate and cache this page on-demand

Difficulty: 6/10

incremental static regeneration, revalidation, on-demand ISR

ISR enables you to use static generation on a per-page basis while revalidating pages in the background as traffic comes in. Incremental Static Regeneration (ISR) enables you to:

1
Update static content without rebuilding the entire site
2
Reduce server load by serving prerendered, static pages for most requests
3
Ensure proper cache-control headers are automatically added to pages
4

What is Incremental Static Regeneration (ISR)?

Difficulty: 6/10

incremental static regeneration, revalidation, on-demand ISR

ISR enables you to use static generation on a per-page basis while revalidating pages in the background as traffic comes in. Incremental Static Regeneration (ISR) enables you to:

1
Update static content without rebuilding the entire site
2
Reduce server load by serving prerendered, static pages for most requests
3
Ensure proper cache-control headers are automatically added to pages
4

What is Incremental Static Regeneration (ISR)?

ISR enables you to use static generation on a per-page basis while revalidating pages in the background as traffic comes in. Incremental Static Regeneration (ISR) enables you to:

What is Incremental Static Regeneration (ISR)?

ISR enables you to use static generation on a per-page basis while revalidating pages in the background as traffic comes in. Incremental Static Regeneration (ISR) enables you to:

Scenario Questions

Follow-up Questions