Next.js 15 has been released, bringing a host of new features and improvements focused on performance, developer experience, and enhanced capabilities. This release marks a significant step forward for the popular React framework.
One of the most notable updates is the stable support for React 19, which allows developers to leverage the latest features of the React library. This includes new hooks like useActionState, useFormStatus, and useOptimistic, which improve the developer experience and UI responsiveness.
Partial Prerendering is another key feature that is now stable. It allows for the shell of a page to be prerendered while dynamic content is streamed in separately, resulting in faster load times and an improved user experience.
Server Actions have been enhanced to simplify server-side logic, allowing developers to handle data fetching and mutations more efficiently directly within their components.
The caching behavior in Next.js 15 has been updated to give developers more control. By default, fetch requests, route handlers, and client-side navigation are no longer cached, allowing for more granular and intentional caching strategies.
The alpha release of Turbopack for production builds promises significantly faster build times, with Vercel reporting up to an 83% improvement over Webpack on multi-core systems.
Next.js 15 also introduces several new APIs, including the after() API for executing tasks after a response has been sent, and experimental APIs like forbidden and unauthorized for more granular authentication error handling.
The framework is also moving towards asynchronous request-specific APIs for handling cookies, headers, and params, which improves performance and pre-rendering capabilities.
Overall, Next.js 15 is a substantial release that empowers developers to build faster, more efficient, and more capable web applications.