how to make the blur effect with react-native?

Try using {ImageBackground} from 'react-native' and set blurRadius={number} like this:

<ImageBackground
      style={{flex: 1}}
      source={require('../assets/example.jpg')}
      blurRadius={90}>
    <Text>Blur background</Text>
</ImageBackground>

https://facebook.github.io/react-native/docs/images.html#background-image-via-nesting https://facebook.github.io/react-native/docs/image.html#blurradius

Now you can do this without any library using the prop: blurRadius.

E.g

<Image
    style={styles.img}
    resizeMode='cover'
    source={imgSrc} 
    blurRadius={1}
/>

Explanation: the number(1) means the amount of blur you want to apply on the image, the higher the number, the blurrier the image.

Unfortunately, this doesn't work on Android yet (RN 0.40.0). Nevertheless, it could be useful to who's looking for only an iOS solution.

Edit: It seems to be working on Android now.