It is supported by almost all latest Browsers.
However, every CSS3 Property uses some predefined prefix for individual browsers, some of them are mentioned below.
-moz- Prefix is used for Mozilla Firefox, so the final code would be -moz-column-count
-o- is used for Opera, so the final code would be -o-column-count
-webkit- is used for Safari, so the final code would be -webkit-column-count
Chrome doesn’t need any prefix, so you can use directly as column-count