@segment/analytics-next/src/core/connection/index.ts

Analytics Next (aka Analytics 2.0) is the latest version of Segment’s JavaScript SDK - enabling you to send your data to any tool without having to learn, test, or use a new API every time.

import { isBrowser } from '../environment'

export function isOnline(): boolean {
  if (isBrowser()) {
    return window.navigator.onLine
  }

  return true
}

export function isOffline(): boolean {
  return !isOnline()
}