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. We typically have a number of projects being worked on at any time, ranging from the more experimental to the clearly defined. Looking ahead, we’d like to start regularly sharing more abo ..read more

React 18 is now available on npm! 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 with support for Suspense. Many of the features in React 18 are built on top of our new concurrent renderer, a behind-the-scenes change that unlocks powerful new capabilities. Concurrent React is opt-in — it’s only enabled w ..read more

Our next major version, React 18, is available today as a Release Candidate (RC). As we shared at React Conf, React 18 introduces features powered by our new concurrent renderer, with a gradual adoption strategy for existing applications. In this post, we will guide you through the steps for upgrading to React 18. If you’d like to help us test React 18, follow the steps in this upgrade guide and report any issues you encounter so we can fix them before the stable release. Note for React Native users: React 18 will ship in React Native with the New React Native Architecture. For more informatio ..read more

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. This was the first time React Conf was hosted online, and it was streamed for free, translated to 8 different languages. Participants from all over the world joined our conference Discord and the replay event for accessibility in all timezones. Over 50,000 people registered, with over 6 ..read more

The React team is excited to share a few updates: We’ve started work on the React 18 release, which will be our next major version. We’ve created a Working Group to prepare the community for gradual adoption of new features in React 18. We’ve published a React 18 Alpha so that library authors can try it and provide feedback. These updates are primarily aimed at maintainers of third-party libraries. If you’re learning, teaching, or using React to build user-facing applications, you can safely ignore this post. But you are welcome to follow the discussions in the React 18 Working Group if you ..read more

2020 has been a long year. As it comes to an end we wanted to share a special Holiday Update on our research into zero-bundle-size React Server Components. To introduce React Server Components, we have prepared a talk and a demo. If you want, you can check them out during the holidays, or later when work picks back up in the new year. React Server Components are still in research and development. We are sharing this work in the spirit of transparency and to get initial feedback from the React community. There will be plenty of time for that, so don’t feel like you have to catch up right now ..read more

Today, we are releasing React 17! We’ve written at length about the role of the React 17 release and the changes it contains in the React 17 RC blog post. This post is a brief summary of it, so if you’ve already read the RC post, you can skip this one. No New Features The React 17 release is unusual because it doesn’t add any new developer-facing features. Instead, this release is primarily focused on making it easier to upgrade React itself. In particular, React 17 is a “stepping stone” release that makes it safer to embed a tree managed by one version of React inside a tree managed by a diff ..read more

Although React 17 doesn’t contain new features, it will provide support for a new version of the JSX transform. In this post, we will describe what it is and how to try it. What’s a JSX Transform? 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. Together with the React 17 release, we’ve wanted to make a few improvements to the JSX transform, but we didn’t want to break existing setup ..read more

Today, we are publishing the first Release Candidate for React 17. It has been two and a half years since the previous major release of React, which is a long time even by our standards! In this blog post, we will describe the role of this major release, what changes you can expect in it, and how you can try this release. No New Features The React 17 release is unusual because it doesn’t add any new developer-facing features. Instead, this release is primarily focused on making it easier to upgrade React itself. We’re actively working on the new React features, but they’re not a part of this r ..read more

Today we are releasing React 16.13.0. It contains bugfixes and new deprecation warnings to help prepare for a future major release. New Warnings Warnings for some updates during render A React component should not cause side effects in other components during rendering. It is supported to call setState during render, but only for the same component. If you call setState during a render on a different component, you will now see a warning: Warning: Cannot update a component from inside the function body of a different component. This warning will help you find application bugs caused by uni ..read more