United Airlines to let travellers use miles for in-flight wi-fi

United Airlines plans to let travellers redeem frequent flyer miles for wi-fi on flights.

The second-largest US airline by capacity has begun testing a web portal that lets customers use award miles to access the internet on their laptops, tablets and smartphones, making it the first US carrier with the feature, a spokesman said.

It hopes to roll out the portal to most US domestic flights by early 2016 and to finish installations on international flights by mid-year. Regional jets that United contracts for its United Express brand will get the portal later.

The move reflects an ongoing push in the airline industry to treat frequent flyer miles like a currency. Travellers already can redeem miles on US carriers for hotel rooms, theatre tickets, goods such as cameras and even identity theft monitoring.

While the airline has shifted its focus towards improving the in-flight experience over maximising revenue, according to United's vice president of e-commerce and merchandising Scott Wilson, it wasn't willing to go as far as entirely free wi-fi.

Wilson said there had to be some dollar or mileage cost because web speeds could slow if each customer tried to access the internet. For now, existing contracts prevent United from rolling out the speediest satellite-based wi-fi on all flights.

Wilson said the miles needed for wi-fi would vary with supply and demand.

United's partner Deutsche Lufthansa AG charges long-haul customers 3500 miles or €9 (A$13.40) for an hour of internet access, according to its website.