Norwegian says it has become the first low-cost airline to launch free WiFi for the full length of long-haul flights.

The service enables passengers to browse the web, check social media and send messages using their own smartphones, tablets and laptops at no cost.

A premium option has an introductory price tag of US$14.95 (11.74 pounds) for three hours - and is being advertised as fast enough to stream music, movies and television.

The Scandinavian carrier has begun rolling out the technology on its Boeing 787-9 Dreamliner and 737 Max aircraft.

The first connected Dreamliner aircraft was delivered last month, and more than half the fleet is due to offer free WiFi by 2020.