Adds the desired vendor prefixes and removes unnecessary ones in your CSS.
/* Here is your CSS with the appropriate prefixes */
You can also see which browsers you choose by filter string on browserl.ist
Autoprefixer is a service for managing vendor prefixes. It adds missing prefixes and deletes obsolete ones. It is recommended by Google and used by Twitter and Taobao.
The autoprefixer uses data on the popularity of browsers and support for vendor prefixes by browsers. Based on this information, it arranges and deletes the prefixes.
You can configure which browsers to generate prefixes for in the distribution. More details on the syntax are in the documentation. There is also a block in the FAQ.