akyl-kb

<link rel="icon" href="/favicons/favicon.ico" type="image/x-icon">

function setFavicon(url) {
    var link = document.querySelector('link[rel=icon]')
    link.setAttribute('href', url)
}

function startAnimation(icons, initial) {
    initial = initial === undefined ? 0 : initial
    setFavicon(icons[initial])
    var next = icons.length <= initial + 1 ? 0 : initial + 1
    setTimeout(function () {
        startAnimation(icons, next)
  }, 1000)
}

var icons = [
    'https://habr.com/images/favicon-32x32.png',
    'https://nextjs.org/static/favicon/favicon.ico'
]

startAnimation(icons)