I always find it ironic that performance on the web is more or less determined by whether you’ve added AD-networks to your site. Ironic in that its usually the companies promoting web performance that are also the ad networks killing it.

I recently stumbled on TNW and was reading an article, and noticed an amount of jank that would actually be difficult to try to purposely do.

For those who want to know, this wasn’t TNW’s fault. Well, they do listen to scroll events which is a no-no, but by all means, its not the end of the world.

The world kind of ends when you open up the dev tools to see whats underneath;

Ten megabytes of data transferred.

So many scripts running from so many domains.

Oh the jank, even chrome is fairly up front about it.

15 + iFrames…

A 231ms pause for javascript execution caused by… Google ad services…

A 220ms script pause caused by…. (drum roll)…


Facebook’s “sdk.js” (unsure what that is) caused multiple 200ms+ pauses for javascript execution. I’m not sure what this is doing, but its impressively intense amount of code to run for it to pause for almost 1/5 of a second.

A full 1.39 seconds to paint the area. This appears to be caused by an ads overlay for the entire screen.

More of the same javascript from 3rd party vendors running a muck.

I wonder how these ad network code are allowed on pages with so many issues, its difficult to know why they spin up so much but they do take an amazingly large amount of time to run.