How Much JavaScript Gets Downloaded... But Never Used?

Every website sends JavaScript to your browser when you visit it. This shows how much of that code just sits there, unused, for different kinds of websites.

Leanest sites (top 10%) 21 KB wasted Pretty good sites (better than most) 87 KB wasted A TYPICAL site (right in the middle) 235 KB wasted Bloated sites (worse than most) 509 KB wasted The worst offenders (top 10% worst) 923 KB wasted
In plain terms: on a typical website, roughly half of the JavaScript code your browser downloads is never even run. It just gets sent over the internet, taking up your data and phone battery, and then... nothing. It was dead weight the whole time.
~44%
of the code a typical site sends you is never used
59%
of the outside code libraries a developer adds to a project turn out to not even be needed
1 in 2
pieces of a project's full dependency tree could be deleted and nothing would break

Sources