import AnimatedNumber from 'react-animated-number';...... class Demo extends Component { ... render () { <AnimatedNumber component="text" value={bigValue} style={{ transition: '0.8s ease-out', fontSize: 48, transitionProperty: 'background-color, color, opacity' }} frameStyle={perc => ( perc === 100 ? {} : {backgroundColor: '#ffeb3b'} )} duration={300} formatValue={n => prettyBytes(n)}/> }}