We all know our users pay a cost when we push our JS framework in to their browser. Now, thanks to Tim Kadlec doing the yeoman’s work of crunching the numbers, we can approximate just how much that cost really is.

There is no faster (pun intended) way to slow down a site than to use a bunch of JavaScript. The thing about JavaScript is you end up paying a performance tax no less than four times:

1. The cost of downloading the file on the network
2. The cost of parsing and compiling the uncompressed file once downloaded
3. The cost of executing the JavaScript
4. The memory cost

Thanks to HTTP Archive, we can figure that out.

I’m pretty happy with how sites using jQuery size up. Granted, it’s not really a UI framework like the others are, but you have to imagine that many of those sites also use jQuery UI and their overall cost still compares well to the more modern solutions.