gulp-uncss is a gulp plugin that can remove unused CSS selectors.
gulp-uncss is a gulp plugin that can remove unused CSS selectors. It can be successfully used in a pipeline that involves other CSS related modifications like compilation, minification, etc.
Example of usage:
var gulp = require('gulp');
var uncss = require('gulp-uncss');
gulp.task('process-css', function() {
  return gulp.src('main.css')
    .pipe(uncss({
      html: ['index.html', 'templates/**/*.html']
    }))
    .pipe(gulp.dest('./build'));
});