React 18 was years in the making, and with it brought valuable lessons for the React team. Its release was the result of many years of research and exploring many paths. Some of those paths were successful; many more were dead-ends that led to new insights. One lesson we’ve learned is that it’s frustrating for the community to wait for new features without having insight into these paths that we’re exploring.

In our last post, we shared step-by-step instructions for upgrading your app to React 18. In this post, we’ll give an overview of what’s new in React 18, and what it means for the future.

Our latest major version includes out-of-the-box improvements like automatic batching, new APIs like startTransition, and streaming server-side rendering...

Last week we hosted our 6th React Conf. In previous years, we’ve used the React Conf stage to deliver industry changing announcements such as React Native and React Hooks. This year, we shared our multi-platform vision for React, starting with the release of React 18 and gradual adoption of concurrent features.

When it’s released, React 18 will include out-of-the-box improvements (like automatic batching), new APIs (like startTransition), and a new streaming server renderer with built-in support for React.lazy.

Browsers don’t understand JSX out of the box, so most React users rely on a compiler like Babel or TypeScript to transform JSX code into regular JavaScript. Many preconfigured toolkits like Create React App or Next.js also include a JSX transform under the hood.

For the past seven years, React upgrades have been “all-or-nothing”. Either you stay on an old version, or you upgrade your whole app to a new version. There was no in-between.