I’ve been dealing with some unfortunate scroll performance issues at work lately, and to aid me in that task I’ve been using a handy CSS stress test bookmarklet made by Andy Edinborough. It works by iterating through all your classes and measuring the performance improvement you get from dropping them – thus helping you find out which classes are making your page scroll speed slow. It’s handy but the use case too constrained for my needs.

I wanted to be able to simply run a test anywhere on the page just for a single run, and I didn’t really care about the classes, since I was manually disabling styles and moving things around, unbinding event etc to find out where the biggest performance improvements could be had.