A few years ago we dug up some data on preprocessor usage on CodePen. That was then and this is now! Back then, we hadn't yet hit 1,000,000 Pens, and we have over 6 million now, so it's much more statistically relevant.

Here's the data as of about the end of 2015.

HTML Preprocessor Usage

See the Pen HTML Preprocessor Usage on CodePen by Chris Coyier (@chriscoyier) on CodePen.

CSS Preprocessor Usage

See the Pen CSS Preprocessor Usage on CodePen by Chris Coyier (@chriscoyier) on CodePen.

JS Preprocessor Usage

See the Pen JS Preprocessor Usage on CodePen by Chris Coyier (@chriscoyier) on CodePen.