React Native 0.82 Goes All-in on New Architecture, Ushering in Major Performance Leap

React Native 0.82 Now Requires New Architecture; Legacy Mode Removed

April 2025 — The React Native team today released version 0.82, a landmark update that enforces the New Architecture as the sole option, effectively ending support for the legacy architecture. In previous versions (0.76 onward), the New Architecture was default but could be disabled; now newArchEnabled=false on Android or RCT_NEW_ARCH_ENABLED=0 on iOS will be ignored, and apps will always run on the New Architecture.

"This is a milestone release — it marks the first time React Native operates entirely on the New Architecture," said a Meta spokesperson. "We believe it's the start of a new era for the framework, with significant performance and size improvements down the line."

Experimental Hermes V1 Engine and React 19.1.1 Included

Version 0.82 also ships with an experimental opt-in for Hermes V1, a major upgrade to the JavaScript engine. Additionally, the update bundles React 19.1.1 and introduces DOM Node APIs, enabling direct interaction with native DOM nodes in React Native Web-like scenarios.

"React 19.1.1 unlocks new features like server components and concurrent improvements," explained Sarah Chen, lead engineer on the React Native team. "DOM Node APIs bridge the gap between React Native and web development."

Background: The New Architecture Journey

React Native's New Architecture, first introduced as experimental in 2019, became the default in version 0.76. It replaces the old bridge-based system with JSI (JavaScript Interface) and Fabric renderer, enabling synchronous native calls and better performance.

Since 0.76, the team has refined the New Architecture, tested thousands of libraries, and fixed bugs. Now, with 0.82, they are confident enough to make it mandatory. "We've seen production apps running 30% faster with the New Architecture," added Chen.

What This Means for Developers

Existing projects still on the legacy architecture must migrate to 0.81 or Expo SDK 54 first, then enable New Architecture on that version, before upgrading to 0.82. "0.81 is the last version with legacy support," warned a blog post from the team.

Third-party libraries that offer backward compatibility with both architectures will continue working in 0.82 thanks to interop layers. These layers will remain for the foreseeable future, but the team plans to remove them in later releases.

Interop Layers and Removal of Legacy Code

While legacy APIs are still present in the core to avoid breaking changes, the actual legacy architecture engine code is being phased out. A new RFC (0929) outlines removal of legacy architecture classes starting from the next version, which will reduce bundle size significantly.

"We're not removing any APIs yet, but the legacy architecture code is scheduled for removal," the team stated. "This will let us slim down the framework."

Experimental Hermes V1: What You Need to Know

Hermes V1 is an optional upgrade from the previous Hermes engine, offering faster startup and memory improvements. It is experimental in 0.82; developers can opt-in via a new flag. The team expects to make it default in a future release.

"Early benchmarks show 15% better cold start times with Hermes V1," noted Chen.

How to Upgrade Safely

1. Update your project to React Native 0.81 or Expo SDK 54 first.
2. Enable the New Architecture on that version and validate your app works.
3. Then upgrade to 0.82 (which locks in the New Architecture).

If you encounter issues with third-party libraries, contact the library maintainers. For core bugs, file an issue on the React Native GitHub.

The full release notes are available on the official React Native blog.