In Universal React based apps, some of the lifecycle methods only run on the client side, e.g componentDidMount. So you just perform client-side-only functions

In Universal React based apps, some of the lifecycle methods only run on the client side, e.g componentDidMount. So you just perform client-side-only functions there. There's also react-no-ssr - https://www.npmjs.com/package/react-no-ssr https://www.npmjs.com/package/react-no-ssr. It is an issue, but one that is really easy to handle.