redactor-rails has a advantage like no need to see preview of html contents.

Add gem

gem 'redactor-rails'

Add to your application.js:

//= require redactor-rails

Add to your application.css:

  *= require redactor-rails

and in your input field need to add a class: "redactor"

thats it.

You can integrate carrierwave with this to save images in apFor more see documentation :