On Demand ISR (Update content without redeploying) is now stable in Next.js 12.2 version On-Demand ISR (Stable).

This feature allows you to create and update static pages after build time down to the per-page level without taking down the whole page to rebuild. This is useful for dynamic content such as a blogging website with a headless CMS.

That's the current implementation that I found in Next.js 12.2 documentation:

// pages/api/revalidate.js



export default async function handler(req, res) {

  // Check for secret to confirm this is a valid request

  if (req.query.secret !== process.env.MY_SECRET_TOKEN) {

    return res.status(401).json({ message: 'Invalid token' });

  }



  try {

    await res.revalidate('/path-to-revalidate');

    return res.json({ revalidated: true });

  } catch (err) {

    // If there was an error, Next.js will continue

    // to show the last successfully generated page

    return res.status(500).send('Error revalidating');

  }

}

Here's a live demo where you can play with this feature: On Demand ISR Demo.

Some video links that I found useful on Youtube.

Next.js 12.1: Introducing On-Demand Incremental Static Regeneration

Next.js On-Demand ISR // Full tutorial