JavaScript version
isBrowser.js
const isBrowser = typeof window === 'object' && typeof document === 'object';TypeScript version
isBrowser.ts
const isBrowser: boolean = typeof window === 'object' && typeof document === 'object';const isBrowser = typeof window === 'object' && typeof document === 'object';const isBrowser: boolean = typeof window === 'object' && typeof document === 'object';