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@fedir
Created May 21, 2013 12:27
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var imageAddr = "http://www.tranquilmusic.ca/images/cats/Cat2.JPG" + "?n=" + Math.random();
var startTime, endTime;
var downloadSize = 5616998;
var download = new Image();
download.onload = function () {
endTime = (new Date()).getTime();
showResults();
}
startTime = (new Date()).getTime();
download.src = imageAddr;
function showResults() {
var duration = (endTime - startTime) / 1000; //Math.round()
var bitsLoaded = downloadSize * 8;
var speedBps = (bitsLoaded / duration).toFixed(2);
var speedKbps = (speedBps / 1024).toFixed(2);
var speedMbps = (speedKbps / 1024).toFixed(2);
alert("Your connection speed is: \n" +
speedBps + " bps\n" +
speedKbps + " kbps\n" +
speedMbps + " Mbps\n" );
}
@rmckeel
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rmckeel commented Oct 16, 2020

For what it's worth, Mozilla still reports Chrome (and by my testing Opera) caps the downlink speed to 10Mb/s to avoid fingerprinting. What a shame web advertisers have ruined specificity on an otherwise helpful feature to determine download speed. In general, the downlink feature can still be used to determine a disadvantaged client (slow downlink) vs a speedy client.

@nehabhomia
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The image/website no longer exists, and therefore this code is broken. It needs to be replaced with an image of the same size.

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