Incremental Static Regeneration (ISR) in Next.js

Sep 26, 2025 |

9 minutes read

Balancing Speed and Freshness with Next.js ISR

Next.js is widely adopted for building React applications because it provides flexibility in rendering approaches, including static site generation, server-side rendering, and the powerful ISR technique. Traditionally, developers had to pick between Static Site Generation (SSG), which creates pages at build time for maximum speed, or Server-Side Rendering (SSR), which generates content on demand for freshness and accuracy. Both methods offer clear benefits: SSG is highly performant, while SSR ensures real-time data.

In practice, most applications need a mix of both speed and up-to-date information. Incremental Static Regeneration (ISR) is applicable in such scenarios. It allows statically generated pages to be refreshed or updated after the initial build, without requiring the entire site to be rebuilt from scratch. This approach gives developers the performance benefits of static rendering while still allowing content to stay current and dynamic.

ISR is particularly useful for large-scale applications such as blogs, e-commerce stores, and news websites, where content changes frequently, but high performance is crucial for user experience.

The Problem with Traditional

To better understand why ISR is necessary, consider the challenges developers face with classic SSG:

Inflexible updates: Static sites generated at build time cannot update pages dynamically. Any content modification requires a redeployment.
High-traffic sites risk stale content: For sites receiving constant traffic—such as news platforms or e-commerce stores—users may encounter outdated pages.
No real-time data: Static sites cannot reflect real-time information, such as live stock updates, comments, or product availability.
Scalability issues for large projects: Generating thousands of pages during each build can lead to long build times, increased hosting costs, and slower release cycles.

These limitations hinder websites from offering both speed and freshness—two key factors for user engagement and SEO rankings.

Challenges with the Traditional Approach

Static sites cannot easily update data without redeploying[Text Wrapping Break]• High traffic blogs/e-commerce apps suffer from stale content[Text Wrapping Break]• Real-time updates are impossible with plain SSG[Text Wrapping Break]• Large-scale projects face long build times and delays in publishing.

How Apollo Client Addresses These Issues

Next.js provides Incremental Static Regeneration (ISR), a feature that enables developers to refresh already generated static pages in the background whenever new requests arrive. This approach blends the speed of static rendering with the adaptability of dynamic rendering, giving you the advantages of both.

Step 1: Enable ISR with getStaticProps

`
export async function getStaticProps() { 
  const posts = await fetch('https://api.example.com/posts').then(res => res.json()); 
  return { 
	props: { posts }, 
	revalidate: 10, 
  }; 
} 
export default function Home({ posts }) { 
  return ( 
	 
  	Latest Posts 
  	{posts.map(post => ( 
    	 
      	{post.title} 
      	{post.body} 
    	 
  	))} 
	 
  ); 
}

Step 2: On-Demand Revalidation

`
export default async function handler(req, res) { 
const { path } = req.query; 
  try { 
	await res.revalidate(path); 
	return res.json({ revalidated: true }); 
  } catch (err) { 
	return res.status(500).send('Error revalidating'); } 
}}[Text Wrapping Break]

Best Practices / Preventive Measures

Choose revalidation intervals wisely: Frequent regeneration increases server load, while infrequent regeneration risks stale content. Analyze your site’s traffic and update patterns.
Use On-Demand ISR for CMS-driven sites: Trigger updates programmatically when new content is published or edited.
Cache API responses: Reduce unnecessary API requests and improve regeneration efficiency.
Monitor ISR logs: Identify and resolve regeneration errors promptly to maintain page integrity.
Combine with Next.js Image Optimization: Use next/image to optimize media alongside ISR for better performance and SEO.
Test regeneration behavior: Validate that both timed and on-demand ISR work as expected in staging environments.

Next.js ISR blends static speed with dynamic updates. Learn how Incremental Static.

The Way Forward

Incremental Static Regeneration in Next.js is a game-changing feature that allows developers to maintain the performance benefits of static pages while also supporting frequent, dynamic updates. By combining timed revalidation and on-demand regeneration, ISR ensures that websites remain both fast and fresh.

For developers and businesses, this means:

Faster page loads and improved SEO
Reduced infrastructure and deployment costs
A better experience for both users and content editors

By adopting ISR, teams can build scalable, high-performance websites that respond to changing content requirements without sacrificing speed or reliability.

Free Consultation

Jignesh Jadav

Sep 26 2025

Jignesh is a recognized Assistant Project Manager at iFlair Web Technologies Pvt. Ltd. Jignesh has over 9 years of industry experience, and in his career, he has managed many web development projects that have been delivered on time with high customer satisfaction. His skills include JS expertise including Angular, React, Vue.js, Mean.js, Next.js, Nuxt.js, and Full-stack tech expertise also in project planning, client communication, and team management, which are a great addition to the company's continuous development and success in the technology industry.