Turbopack Production Builds in Next.js

In the ever-evolving landscape of web development, build tools are paramount for achieving optimal performance. While Webpack has long been the standard bundler for Next.js, Vercel has been diligently developing Turbopack, a revolutionary Rust-based bundler promising dramatically faster build times.

We've previously explored the comparison between Turbopack and Webpack, primarily focusing on the development experience. However, a major milestone has arrived with the release of Next.js 15.3: an exciting alpha release introducing Turbopack for production builds (next build --turbopack). This is a significant step towards leveraging Turbopack's speed benefits, already used in over 50% of Next.js 15 development sessions, for the critical production process.

This marks a significant step towards bringing the speed benefits of Turbopack, which over 50% of development sessions on Next.js 15 are already using, to the production build process.

Trying Out Turbopack Production Builds in 15.3

You can start experimenting with Turbopack builds in Next.js 15.3 today. After upgrading to 15.3, simply run your build command with the --turbopack flag:

next build --turbopack

This simple addition to your build command is all that's needed to instruct Next.js to use the Turbopack engine for generating your production-ready application.

Current Functionality and Progress

As an alpha release, it's important to note that this feature is still under active development. However, the progress is promising, with 99.3% of integration tests for next build already passing. You can monitor the progress towards full compatibility at areweturboyet.com.

If your application is already compatible with Turbopack for development, it is expected to work with the build command as well.

Given this promising progress and alpha status, it's crucial to understand the current state and recommended use cases.

Important Consideration: Given its alpha status, Vercel does not recommend using Turbopack for production builds in mission-critical applications at this stage. It's best suited for testing in preview or staging environments, or for running locally to compare bundle sizes and performance against the standard Webpack build.

The team is diligently working to achieve 100% compatibility and close any performance gaps through various optimizations like scope hoisting and improved chunking.

Performance Improvements Observed

One of the most compelling aspects of Turbopack is its performance potential, especially when leveraging multi-core processors. Vercel has observed significant speedups compared to the previous Webpack implementation:

• At 4 CPU cores: 28% faster than Webpack
• At 16 CPU cores: 60% faster than Webpack
• At 30 CPU cores: 83% faster than Webpack

These significant speedups translate directly into faster deployment cycles, quicker feedback loops for developers, and potential cost savings on CI/CD infrastructure. These numbers highlight Turbopack's ability to parallelize tasks more effectively. Furthermore, experimental work on persistent caching is underway, which is expected to further reduce build times in the future.

Ecosystem Compatibility

Ensuring compatibility with the broader Next.js ecosystem is a key focus before the stable release. Vercel is collaborating with commonly used integrations, such as Sentry, to ensure they work seamlessly with next build --turbopack. Tool authors are encouraged to reach out to the Next.js team for assistance in ensuring their libraries are compatible.

Conclusion

The alpha release of Turbopack production builds in Next.js 15.3 is an exciting development for the Next.js ecosystem. While not yet production-ready, it offers a compelling glimpse into the future of faster build times, especially for projects leveraging multi-core machines.

We strongly encourage developers to try out this alpha feature in non-critical environments, provide valuable feedback, and closely follow the exciting progress at areweturboyet.com. As development continues and compatibility rapidly improves, Turbopack is undeniably poised to become a true game-changer for Next.js build performance in the near future.