[scott113341]

An additional problem is that even when CSS is properly scoped, you end up with wasted bits over the wire by sending down duplicated declarations. I did some cursory research using cssstats [1] because I was curious how many CSS declarations are unique. Turns out it's about 20-25% for most "big tech" websites.

Gzip helps reduce the impact of this, but Styletron's gzipped CSS is still much (40% or so) smaller than the other CSS-in-JavaScript implementations [2]. In some cases, the cost of switching to using a tool like Styletron might be justified by faster loading times in low-bandwidth markets.

[1] http://cssstats.com

[2] https://ryantsao.com/blog/virtual-css-with-styletron

[matchu]

Bandwidth was the major motivation for building Aphrodite, too: Khan Academy wanted to decrease the number of bytes required for the initial pageload. http://engineering.khanacademy.org/posts/aphrodite-inline-cs...

> We must deliver the absolute minimum amount of CSS necessary by only sending down CSS in use by components in the server-side rendered body. This rules out extracting all the CSS used in all of our components at compilation time, as much of that CSS would not be needed for the initial page load.

Colocating styles with components is a win, but, more importantly, styles-as-JS-objects was the simplest way to get this perf feature out the door.

[kowdermeister]

Faster load times is bit of a stretch. While it's true that up to 40% sounds good, but we are talking about a few kbytes here meanwhile images penalize you much much more on load time. And what do we sacrifice? Mixing concepts that shouldn't be mixed in the first place.

Duplicated styles also compress better with gzip as you said. Do you think stripping a few kbytes is worth turning your whole process upside down?