Gst for freelancers/it companies exporting services abroad

Hello Guys,

I have many clients who are freelancer's or small IT companies exporting web design/development services to clients outside India. Do they have to register under GST and also charge clients 18%?

Can any one provide any information under this. I earlier thought export of services outside india is exempt from any Direct Taxes. But there is a dilemma around GST?

Any inputs/suggestion would be helpful.