Animation

Learn how to integrate the react-native-reanimated library and use it in your Expo project.

Animations are a great way to enhance and provide a better user experience. In your Expo projects, you can use the Animated API from React Native. However, if you want to use more advanced animations with better performance, you can use the react-native-reanimated library. It provides an API that simplifies the process of creating smooth, powerful, and maintainable animations.

Installation

To install react-native-reanimated, run the following command:

After the installation completes, add the Babel plugin to babel.config.js:

module.exports = function (api) {
  api.cache(true);
  return {
    presets: ['babel-preset-expo'],
    plugins: ['react-native-reanimated/plugin'],
  };
};

After you add the Babel plugin, restart your development server and clear the bundler cache using npx expo start --clear.

If you load other Babel plugins, the Reanimated plugin has to be the last item in the plugins array.

Web support

For web, install the @babel/plugin-proposal-export-namespace-from Babel plugin and update the babel.config.js to load it:

plugins: [
  '@babel/plugin-proposal-export-namespace-from',
  'react-native-reanimated/plugin',
],

After you add the Babel plugin, restart your development server and clear the bundler cache using npx expo start --clear.

Minimal example

The following example shows how to use the react-native-reanimated library to create a simple animation. For more information on the API and its usage, see react-native-reanimated documentation.

import Animated, {
  useSharedValue,
  withTiming,
  useAnimatedStyle,
  Easing,
} from 'react-native-reanimated';
import { View, Button, StyleSheet } from 'react-native';

export default function AnimatedStyleUpdateExample() {
  const randomWidth = useSharedValue(10);

  const config = {
    duration: 500,
    easing: Easing.bezier(0.5, 0.01, 0, 1),
  };

  const style = useAnimatedStyle(() => {
    return {
      width: withTiming(randomWidth.value, config),
    };
  });

  return (
    <View style={styles.container}>
      <Animated.View style={[styles.box, style]} />
      <Button
        title="toggle"
        onPress={() => {
          randomWidth.value = Math.random() * 350;
        }}
      />
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    flexDirection: 'column',
  },
  box: {
    width: 100,
    height: 80,
    backgroundColor: 'black',
    margin: 30,
  },
});

Other animation libraries

Other animation packages are available, such as Moti, that you also use in your Expo project and work on Android, iOS, and the web. For more information on its API and usage, see Moti's documentation.