SOURCE

/* eslint-disable */
function init() {
    cvs.height = window.innerHeight, cvs.width = window.innerWidth;
    var t = cvs.width / fontSize;
    charSet = 'W I S H 3 D E A R T H', charSet = charSet.split('');
    for (var n = 0; t > n; n++) drops[n] = Math.floor(Math.random() * cvs.height)
}

function rain() {
    ctx.fillStyle = 'rgba(0, 0, 0, 0.05)', ctx.fillRect(0, 0, cvs.width, cvs.height);
    for (var t = 0; t < drops.length; t++) {
        var n = charSet[Math.floor(Math.random() * charSet.length)];
        ctx.fillStyle = altiColor(), ctx.fillText(n, t * fontSize, drops[t] * fontSize), Math.random() > 0.99 && (drops[t] = 0), drops[t]++
    }
}

function altiColor() {
    var t = ['#FFF', '#69A3D5'];
    return t[Math.floor(3 * Math.random())]
}
var cvs, ctx, charSet, drops = [], font = 'arial',
        fontSize = 10;
window.onload=function(){
    cvs=document.getElementById('canvas111');
     ctx = cvs.getContext('2d');
    ctx.font = fontSize + 'px ' + font, init(), setInterval(rain, 40), window.addEventListener('resize', function (t) {
        init()
    })
}

<canvas id="canvas111" height="947" width="1920"></canvas>

body {
  margin: 0;
}