How to disable asset logging in development mode, on rails?

put this in config / initializers / quiet_assets.rb

if Rails.env.development?
  Rails.application.assets.logger = Logger.new('/dev/null')
  Rails::Rack::Logger.class_eval do
    def call_with_quiet_assets(env)
      previous_level = Rails.logger.level
      Rails.logger.level = Logger::ERROR if env['PATH_INFO'] =~ %r{^/assets/}
      call_without_quiet_assets(env)
    ensure
      Rails.logger.level = previous_level
    end
    alias_method_chain :call, :quiet_assets
  end
end

his rather general solution to this problem

can also use gem

gem 'quiet_assets', :group => :development