What is css-minification-benchmark?

A comparison of CSS minification engines.

FAQ

Which engines are covered?

• clean-css
• crass
• css-condense
• cssnano
• csso
• cssshrink
• csswring
• more-css
• ncss
• sqwish
• ycssmin

What are the results?

Most of the time more-css comes first although clean-css and csso come close. Test the minifiers with your CSS to find what works best for you.

How can I see the results?

Clone the repository first then run ./bin/bench. That's it!

Note that on Windows you will need to do node ./bin/bench

If you prefer to see results without cloning the repo here are the most recent ones.

How can I generate the html report?

Just run ./bin/bench --html > report.html

How can I test my CSS file?

Just copy your file to the data directory (make sure the filename ends with .css) and re-run the benchmark.

Please make sure your file does not contain any special comments (/*! ... */) since not all minifiers strip them correctly:

• clean-css is configurable, but leaves all by default
• csso always leaves one
• ncss and ycssmin always leave all

Can I get the total size and time for my CSS files?

Copy all your files to the data directory like before and run the benchmark with --total.

How can I add a new minifier to the list?

• add it to package.json as a devDependency
• run npm install
• require it in lib/minify.js and add it to minifiers hash
• run npm run bench
• add it to this file in "Which engines are covered?" section above
• send a PR (if you wish to have it included)

How can I compare a subset of minifiers?

Just run ./bin/bench --only ncss,ycssmin (it's turned into /.*(ncss|ycsmin).*/ regex)

Can I get the compressed gzip size as well?

Run ./bin/bench --gzip to measure the gzip size instead of the regular file size.

License

css-minification-benchmark is released under the MIT License.