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How do they do it?

large images



12:24 am on Mar 6, 2013 (gmt 0)

Hi, Can anyone explain to me how they manage to load such large images so quickly? The file size in Pingdom says 1.4kb but the actual file is 140kb, then they seem to expand it.



3:08 am on Mar 6, 2013 (gmt 0)

WebmasterWorld Senior Member 10+ Year Member

The actual size is 140kb and thereabouts. They aren't expanding it. They probably load the additional images in the background while you view the first one.


3:36 am on Mar 6, 2013 (gmt 0)

Thanks, so I guess they stretch the image to match the screen size dynamically. Must be a fine line between compression and file size...


5:02 am on Mar 6, 2013 (gmt 0)

5+ Year Member

Background images are 980px wide. Only the first one is loaded instantly, the rest gets injected through javascript. You can monitor the process yourself, just go to the webpage with chrome, hit inspect element and scroll to the bottom, there is a div with an id of "supersized", it contains ul with just one li, the rest of the li-s get injected through javasript after some time for rotation.

Don't rely on pingdom numbers, they are not accurate for pages with heavy javascripts.


5:15 am on Mar 6, 2013 (gmt 0)

Thanks for that! nice tip with the Chrome too... you can see the images loading thanks :)

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