<body>
<h1 id="result"></h1>
<script>
let img = new Image();
img.src = "./blank.jpg";
img.onload = () => {
document.getElementById('result').innerText = 'loaded';
}
img.onerror = () => {
document.getElementById('result').innerText = 'blocked';
}
document.body.appendChild(img);
</script>
</body>