How to use `<FormattedMessage>` as placeholder using React Intl?

The <Formatted... /> components from react-intl return elements, not plain text, so they can't be used for placeholders, alt text, etc. In that case, you should use lower level API formatMessage(). You can inject the intl object into your component using injectIntl() higher-order component and then format the message using formatMessage() available on that object.

import React from 'react';
import { injectIntl, intlShape } from 'react-intl';

const MyComponent = ({ intl }) => {
  const placeholder = intl.formatMessage({ id: 'messageId' });
  return <input placeholder={placeholder} />;
};

MyComponent.propTypes = {
  intl: intlShape.isRequired,
};

export default injectIntl(MyComponent);