Exploring Next.js 15.4 and Turbopack: Faster Build

Next.js 15.4 is here, and one of the exciting updates is the introduction of Turbopack Builds, which is now stable and available via next build --turbopack. While it's still marked as beta, this feature offers a glimpse into the future of Next.js builds, replacing Webpack with the much faster Turbopack.

Build Time Comparison

I recently gave this a try in one of my company projects. After upgrading from Next.js 15.2.4 to 15.4.4 and enabling Turbopack for the build step, the result was a significant speed improvement:

• Next 15.2.4 (Webpack): ~1 minute 8 seconds
• Next 15.4.4 (Turbopack): ~29 seconds

That's more than a 50% reduction in build time. While the Next.js team still doesn't fully recommend it for production just yet, the performance gains are great. They do state it's stable and actively use it for vercel.com, which speaks volumes about their confidence in its capabilities.

What's Next?

The groundwork done in Next.js 15.4 is setting the stage for an even more powerful Next.js 16. Some of the features that are coming soon are:

• Turbopack Builds (Beta): Expect Turbopack to be fully production-ready and potentially the default build tool.

• Cache Components (Beta): A unified approach to caching features to further optimize performance.

• Optimized Client-Side Routing: Better prefetching and improved cache invalidation within the App Router for faster navigation.

• Enhanced DevTools & Debugging: Better tools to inspect and debug your Next.js applications.

• Node.js Middleware (Stable): Robust Node.js runtime support for Middleware.