| Site | CSS Optimiser | Icey Compressor | Flumpcakes | Clean CSS |
| Digg.com | failed | failed | failed | 16.8% |
| Slashdot | 17.45% | 51.21% | 9% | 21.9% |
| Filmsy | 18.85% | 47.08% | 17% | 29.1% |
| iBegin | failed | 55.95% | failed | failed |
| Download.com | failed | 45.49% | 0% | 27.9% |
| ESPN | failed | 69.84% | failed | 27.9% |
| Average: | 18.15% | 53.91% | 8.67% | 24.18% |
The clear winner here is Icey’s CSS Compressor, blowing away the rest. It even shows the compressed code with color coding, making it easier to see the changes they made and how its formatted. It also makes it easier to read that the output of most other tools.
In second place seems to be CleanCSS which is based on csstidy 1.1. It also shows syntax highlighting which makes it easy to understand. They also list the changes they made, and any errors they noticed.
In third comes CSS Optimizer which is one of the simplest of them all. It does not have the bells and whistles of the previous two, but is much nicer looking than our last place entrant, Flumpcakes CSS Optimiser.
Flumpcakes has a few more options than CSS Optimiser, but it does not have the same simple look. The results page in my personal opinion is ugly, and does not even tell the unit of measurement used for comparison.
Conclusions
CSS optimization is a very valid form of speeding up downloads without having to sacrifice much (just legibility). With the average dialup user downloading at 3kb/s, savings of just 10kb can mean the page loads a stunning 3 seconds faster. And just imagine ESPN with savings of almost 18kb. Multiple by the large traffic the site gets, and those are some real solid promotion-worthy savings. So while this may not be important whilst you use a broadband connection, just you wait until you go visit your grandparents.

