Performance

Abstract

CSS files are (typically) small files with (typically) simple syntax. It might seem that where performance is concerned there is little to be done to make a difference, and that improvements will be slight. In many cases, this may be true. However, when we are dealing with CSS at a grander scale, where our files may be reaching larger sizes and we expect them to be served millions or tens of millions of times a day, small improvements make big differences—both to the user and the developer. One kilobyte may seem a tiny amount of data by today’s standards, but do the math—those kilobytes soon add up to gigabytes of data that the business needs to pay for in bandwidth. And when we are considering the payload the user downloads and the speed of the page rendering, it is a truism to say that every little bit counts.