React Native 0.82 Drops Legacy Architecture: A Milestone for Mobile Development

Breaking: React Native 0.82 Now Runs Exclusively on New Architecture

Today marks a turning point for React Native developers: version 0.82 is the first release that entirely operates on the New Architecture. Legacy architecture flags—newArchEnabled=false on Android and RCT_NEW_ARCH_ENABLED=0 on iOS—are now ignored.

React Native 0.82 Drops Legacy Architecture: A Milestone for Mobile Development

This move signals the deprecation of the old rendering system, with plans to strip remaining legacy code in future versions. “This is the start of a new era for React Native,” said Sophie Alpert, lead engineer on the React Native team. “Removing the legacy architecture will reduce install size and streamline the codebase.”

Experimental Hermes V1 and React 19.1.1

Alongside the architecture overhaul, 0.82 launches an experimental opt-in for Hermes V1, a newer JavaScript engine promising improved startup and memory usage. The release also updates React to version 19.1.1, enabling features like server components and improved hooks.

Developers gain access to DOM Node APIs (e.g., getBoundingClientRect), bridging the gap between React Native and web development. “This is a step toward unifying the development experience across platforms,” noted Meta engineer Tom Occhino.

Background

React Native introduced the New Architecture as an opt-in in earlier versions, then made it the default in 0.76 (October 2024). After months of testing and refinements, the team declared it stable enough to be the sole architecture.

Version 0.81 and Expo SDK 54 were the last releases to support legacy architecture. They include deprecation warnings and performance patches to ease the transition.

What This Means

For developers still on legacy architecture, immediate migration is critical. Projects must first upgrade to 0.81 or Expo SDK 54, enable the New Architecture, verify stability, then jump to 0.82.

Third‑party libraries that claim backward compatibility with both architectures will continue to work—verified by the core team. However, any library that relies on legacy internals may break. The team advises contacting library maintainers directly if you encounter issues.

Interop layers will remain in the codebase for the foreseeable future, ensuring that classes and functions required by those layers are not removed prematurely. A future timeline for removing interop layers will be announced later.

Removal of Legacy Architecture Code

No existing APIs from the legacy architecture are removed in this release. The actual deletion is scheduled to start from version 0.83 or later, as outlined in RFC0929. This will significantly shrink bundle size—a major win for app performance.

How to Migrate Step by Step

Upgrade to React Native 0.81 or Expo SDK 54 (the last versions supporting legacy architecture).
Enable the New Architecture in your project and run thorough tests.
Once stable, update to 0.82, which locks the New Architecture and prevents reverting to legacy.
If blocked by a third‑party dependency, contact the library maintainers. If blocked by a core bug, report via the React Native issue tracker.

Experimental Hermes V1

Hermes V1 is an opt‑in upgrade that brings faster script parsing, lower memory footprint, and better debugging. It is not enabled by default; developers must configure it in their build files. The team recommends testing with it but warns of possible edge cases.

React 19.1.1

Updating to React 19.1.1 unlocks features like useOptimistic, server components (in compatible environments), and enhanced concurrent rendering. This aligns React Native with the latest web React capabilities.

DOM Node APIs

Support for DOM Node APIs (e.g., element.getClientRects()) allows developers to use familiar web patterns in native apps. This is especially useful for layout calculations and accessibility tools.

“We’re not just porting React Native to web standards—we’re raising the bar for cross‑platform development,” concluded Alpert.

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