JavaScript does not allow you to do cross-domain call but you can test if a site is up or down using this script:
function checkServerStatus( url )
    var script = document.body.appendChild(document.createElement("script"));
    script.onload = function()
        alert( url + " is online");
    script.onerror = function()
        alert( url + " is offline");
    script.src = url;

checkServerStatus( "" );
checkServerStatus( "" );

I found this code at

We want an external (cross domain) website to be fitted into a fixed size container (iframe). We can achieve this using CSS3 transform scale property.

Step 1: Decide how the external website to look like. Let say 1600 × 900
<iframe src="" width="1600" height="900"></iframe>

Step 2: Remove scroll bar (optional)
<iframe src="" width="1600" height="900" scrolling="no"></iframe>

Step 3: Let say we want to shrink from 1600 × 900 to 400 × 225. So 400 ÷ 1600 = 0.25. We also need the transform origin to be at top left
<iframe src="" width="1600" height="900" scrolling="no" style="transform:scale(0.25); transform-origin:0 0;"></iframe>

Sample code on how to monitor several blogs using iframe:


Topic alias: external website monitoring, thumbnail website, website preview