Postprocess Less using pleeease.

npm install -g less-plugin-pleeease

and then on the command line,

lessc file.less --pleeease="browsers"

The browsers are a comma seperated list of browsers as specified with autoprefixer. Allows you to override many options in one go. Accept same value as autoprefixer.browsers and override it, based on CanIUse database (exactly as Autoprefixer).

See pleeease for the complete documentation.

var LessPluginpleeease = require('less-plugin-pleeease'),
    pleeeasePlugin = new LessPluginpleeease({browsers: ["IE 9"]});
    less.render(lessString, { plugins: [pleeeasePlugin] })
  .then(

Browser usage is not supported at this time.