Share data between react app in browser tabs ( must be same protocol, origin and port) , https://dev.to/kamalhossain/send-data-between-tabs-in-react-app-2ehi

browser-tab-broadcast-react.js

import React from 'react'
import './App.css'

function App() {
  const [isOpnnedAlready, setIsOpnnedAlready] = React.useState(false)

  const channel = React.useMemo(() => new BroadcastChannel('couldBeAnything'), [])

  React.useEffect(() => {
    channel.postMessage({
      isOpnnedAlready: true,
    })
    channel.addEventListener('message', (e) => {
      setIsOpnnedAlready(e.data.isOpnnedAlready)
    })
    return channel.close
  }, [])

  function refreshPage() {
    window.location.reload()
  }
  return (
    <div class="App">
      {!isOpnnedAlready ? (
        <h1>Something happening in the dom</h1>
      ) : (
        <>
          <p>Only one tab could open at a time</p>
          <button type="button" onClick={refreshPage}>
            <span>Reload</span>{' '}
          </button>
        </>
      )}
    </div>
  )
}
export default App

package.json

{
  "name": "browser-tab-broadcast-react",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^5.11.6",
    "@testing-library/react": "^11.2.2",
    "@testing-library/user-event": "^12.5.0",
    "react": "^17.0.1",
    "react-dom": "^17.0.1",
    "react-scripts": "4.0.1",
    "web-vitals": "^0.2.4"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}