How to check is Server or Client in Nodejs?

When you create an app with Nodejs, sometime you'd like to check a component is running on Client or Server to handle the logic code. The short piece of code bellow may help you handle this.

Create a helper isServer

const isServer = !(
  typeof window !== 'undefined' &&
  window.document &&


In the helper, we use the window object to check, if is Server, the type of the window will be undefined and the window properties is undefined also.


	// server logic handle
	// client logic handle

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