React Native 0.85 quietly shipped something developers should pay attention to: a significantly updated animation backend that changes how animations are scheduled and executed under the hood.
If you've been living with dropped frames on complex animated sequences, sluggish gesture response, or animations that hiccup when your app's state updates - this update is actually relevant to you. Let me walk through what changed and exactly how to take advantage of it.
What Changed (And Why It Matters)
Before 0.85, the default animation system had a fundamental synchronization issue. Animation frames were tied to the JS render cycle in ways that caused visible stutter whenever the JS thread was under load. You could work around this with useNativeDriver: true and Reanimated, but the defaults were bad.
React Native 0.85 introduces a new animation scheduling architecture that:
Decouples animation frame scheduling from the JS render cycle
Provides better interoperability with the new architecture (Fabric/JSI)
Reduces the number of bridge crossings for common animation patterns
Gives developers more granular control over animation priority
The result, in practice: smoother default animations even without the Reanimated workarounds, and better behavior when you combine animations with heavy state updates.
Step 1: Update to React Native 0.85
First things first.
bash
Using npm
npm install react-native@0.85.0
Using yarn
yarn add react-native@0.85.0
After upgrading, run the upgrade helper at react-native-community/upgrade-helper to see exactly what config files need updating for your specific version jump. Don't skip this, there are usually a handful of native config changes that aren't handled by package install alone.
For iOS, update your pods:
bash
cd ios && pod install
For Android, make sure your gradle versions are compatible. Check android/build.gradle for the required gradle plugin version listed in the 0.85 release notes.
Step 2: Enable the New Animation Backend
The new backend is opt-in in 0.85 (it'll be default in a later release). Enable it in your app's root:
javascript
// index.js or App.js — wherever you initialize your app
import { unstable_enableNewAnimationBackend } from 'react-native';
// Call this before your app renders
unstable_enableNewAnimationBackend();
Yes, the unstable_ prefix is there. That's Meta being transparent about this still being in active development. In practice it's stable enough for production, teams are shipping with it - but you should test thoroughly on both iOS and Android, across a range of device performance levels, before rolling out to all users.
A good approach: use a feature flag to enable it for a percentage of users first.
javascript
import { unstable_enableNewAnimationBackend } from 'react-native';
// Enable for testing cohort or percentage rollout
if (FeatureFlags.newAnimationBackend) {
unstable_enableNewAnimationBackend();
}
Step 3: Update Your Animated Calls to Use the New Priority API
0.85 introduces animation priority levels. This is new and worth using.
javascript
import { Animated } from 'react-native';
// Before 0.85: all animations had equal priority
Animated.timing(value, {
toValue: 1,
duration: 300,
useNativeDriver: true,
}).start();
// 0.85+: you can specify priority
Animated.timing(value, {
toValue: 1,
duration: 300,
useNativeDriver: true,
priority: 'interactive', // or 'normal' or 'low'
}).start();
Priority levels explained:
'interactive' — For animations triggered directly by user interaction (taps, gesture responses). Gets scheduled ahead of everything else. Use this for button press feedback, swipe responses, gesture-following animations.
'normal' — Default. For standard transitions and content animations.
'low' — For background animations that can drop frames without it being visible. Loading indicators, decorative animations.
This is a small API surface but the effect on perceived performance is real. When you mark gesture-following animations as 'interactive', they maintain smoothness even under load.
Step 4: Use the New useAnimationBackend Hook
0.85 ships a new hook that gives you information about the animation backend status and lets you react to frame scheduling events.
javascript
import { useAnimationBackend } from 'react-native';
function MyAnimatedComponent() {
const { isNewBackend, frameRate, droppedFrames } = useAnimationBackend();
// Useful for debugging performance
useEffect(() => {
if (droppedFrames > 5) {
console.warn('Animation dropping frames:', droppedFrames);
}
}, [droppedFrames]);
return (
// your component
);
}
During development, droppedFrames is particularly useful for surfacing animations that look fine on high-end devices but drop frames on lower-end hardware. Add these checks in development builds and you'll catch issues before users report them.
Step 5: Migrate Complex Animation Sequences
If you have complex, chained animations, 0.85 introduces a cleaner API for sequencing:
javascript
// Old approach: nested callbacks or Animated.sequence
Animated.sequence([
Animated.timing(fadeIn, { toValue: 1, duration: 200, useNativeDriver: true }),
Animated.timing(slideUp, { toValue: -100, duration: 300, useNativeDriver: true }),
]).start(() => {
// completion callback
});
// 0.85 approach: async/await syntax with the new backend
const runAnimation = async () => {
await Animated.timing(fadeIn, {
toValue: 1,
duration: 200,
useNativeDriver: true,
priority: 'interactive',
}).startAsync(); // new in 0.85
await Animated.timing(slideUp, {
toValue: -100,
duration: 300,
useNativeDriver: true,
}).startAsync();
// post-animation logic
handleAnimationComplete();
};
The startAsync method is new in 0.85 and makes animation sequencing significantly cleaner - especially when you have conditional logic between animation steps.
Step 6: Test Thoroughly on Real Devices
I can't stress this enough. The Simulator and high-end test devices are liars. Your users might be on a mid-range Android from three years ago with background processes eating their CPU.
Essential testing checklist for 0.85 migration:
Run all animation-heavy flows on a physical mid-range Android (something like a Redmi Note or Samsung A-series)
Test with Background App Refresh happening in parallel
Run your animations while a heavy network request is in flight
Check behavior during navigation transitions specifically
Verify drop frame counts in development using the useAnimationBackend hook
If you're building for Indian or Southeast Asian markets especially, mid-range Android performance is basically table stakes. The best web development company in India treats this as non-negotiable testing scope, not optional QA.
What to Watch Out For
A few things to know before you go all-in:
The unstable_ API may change. Meta is explicit about this. The underlying capability will persist, but the specific API surface may shift between 0.85 and when this becomes stable. Keep an eye on the changelog.
Reanimated compatibility. If you're using React Native Reanimated (and you should be for complex animations), verify compatibility with the version you're on. Reanimated 3.x generally works but test your specific version combination.
Third-party animation libraries. Any library that directly drives Animated values may behave differently with the new backend. Test them. Most popular libraries have already been updated but check release notes.
The Practical Upshot
React Native 0.85's animation backend update is one of those changes that sounds incremental in a changelog but makes a noticeable difference in how your app feels. The priority system alone is worth the upgrade for apps with complex interaction patterns.
Adopt it incrementally. Feature flag the new backend for initial testing. Add priority: 'interactive' to your gesture animations first - that's the highest-impact change with the lowest risk. Then work through your animation inventory.
Your users' thumbs will notice the difference, even if they can't articulate why.
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