Performance is critical in modern web development, and Next.js 15 introduces several enhancements to help developers build faster, more efficient applications. In this post, we’ll explore some best practices and new features in Next.js 15 that can take your app’s performance to the next level.

1. Edge Rendering for Dynamic Content

Next.js 15 leverages Edge Functions to bring rendering closer to your users. This means your dynamic content can now be served with near-instantaneous speed, reducing latency significantly.

How to Use:

export const config = {
  runtime: 'edge',
};

export default function handler(req: Request) {
  return new Response('Hello from the edge!');
}

Why It Matters:

• Faster load times for users worldwide.

• Reduced time-to-first-byte (TTFB).

• Ideal for applications with global audiences.

2. Improved Image Optimization

The Next.js Image component has been updated to include advanced compression techniques and support for more formats like AVIF and WebP2. These formats reduce file sizes while maintaining high-quality visuals.

Best Practices:

• Use the priority attribute for critical images.

• Leverage the fill layout for responsive designs.

• Host your images on a CDN for faster delivery.

3. Route Caching with App Router

With the App Router, you can now cache entire routes or specific segments. This is particularly useful for static-heavy pages with some dynamic sections.

Example Configuration:

export const runtime = 'experimental-cache';
export const revalidate = 60; // Cache for 60 seconds

Benefits:

• Reduced server workload.

• Faster navigation for returning users.

• Seamless integration with ISR (Incremental Static Regeneration).

4. Parallel and Streaming Rendering

Next.js 15 introduces React Server Components (RSC) and streaming capabilities to render parts of your UI as soon as the data is ready.

Use Case:

Render product listings while waiting for less critical data like user reviews:

export default async function Page() {
  const products = await getProducts();
  return (
    <div>
      <Products data={products} />
      <Suspense fallback={<Loading />}>
        <Reviews />
      Suspense>
    div>
  );
}

5. Prefetching with Turbo Mode

Next.js 15’s Turbo Mode enhances the built-in link prefetching, making navigation feel instantaneous even on slower networks.

Key Takeaway:

Ensure you use the component to automatically prefetch linked pages, or enable experimental.turbo in your next.config.js.

Conclusion

Next.js 15 provides a plethora of tools to help developers optimize performance without adding complexity. By adopting edge rendering, improved image optimization, route caching, and React Server Components, you can build applications that are lightning-fast and scalable.