Expo SDK 55 Released for React Native
Expo announced the release of SDK 55, a major upgrade for cross-platform app developers. The update bundles React Native 0.83 and React 19.2, and introduces a powerful new Expo Router v7 with native toolbars, zoom transitions, and server-side rendering capabilities.
A significant architectural shift in Expo SDK 55 is the complete removal of support for the legacy architecture, making the New Architecture the mandatory default. This change aligns with the core direction of React Native, which froze the legacy architecture in version 0.80 to focus on improved performance and capabilities. The bundled React 19.2 introduces the `<Activity />` component, a powerful tool for preserving state in hidden UI elements. This allows developers to keep form data or scroll positions intact on inactive tabs, preventing data loss as users navigate through different parts of an application. Developer tooling receives a major upgrade thanks to React Native 0.83, which stabilizes a subset of the Web Performance APIs. New DevTools now feature dedicated network and performance panels within a standalone desktop app, giving clear visibility into API calls and JavaScript execution to debug bottlenecks. The update also brings more robust Server-Side Rendering (SSR) to the ecosystem. In addition to Expo Router's new data loaders for SEO-optimized web pages, React 19.2 enhances the user experience by batching how server-rendered Suspense boundaries are revealed, making content appear more smoothly and consistently. Beyond the core, individual packages see key improvements. The `expo-blur` library is now stable and highly performant on Android 12 and newer by leveraging the RenderNode API. SDK 55 also introduces a new versioning scheme where all core Expo package versions now align with the SDK's major version number, simplifying dependency management. Support for integrating Expo into existing native codebases, known as "brownfield" development, is enhanced with a new `expo-brownfield` package. It enables an "isolated" approach where the React Native portion of an app can be packaged as a native library (AAR or XCFramework), allowing native developers to use it without needing a Node.js environment.
