In-flight internet access is shaping up as a key battleground for Australia's two major airlines, with Virgin Australia announcing a trial of on-board Wi-Fi to match the service Qantas is close to launching.

Virgin on Thursday revealed plans to offer passengers Wi-Fi by connecting to Optus satellites on domestic and New Zealand flights and to global network providers Intelsat and SES for other international flights.

The airline said it would next month begin a three-month trial of the technology on a single Boeing 737-800, its domestic workhorse, with installation of 2Ku antennas across its full fleet of 737-800s, 777s and Airbus A330s to follow.

Qantas is close to launching its own Wi-Fi services across its domestic fleet of 737s, which will connect to NBN satellites. It had intended to start offering the service to some customers this week, but pushed the launch back because of "stability issues".

Qantas said it remained on track for a domestic rollout from mid-year, but has not yet announced Wi-Fi plans for its international fleet.

Virgin said passengers would connect their devices to the internet for free during the three-month trial, but had not decided whether it would charge for access after that. It would base that decision on customer feedback and performance results from the trial, it said. Qantas has promised its Wi-Fi will be free.

Virgin is partnering with airline connectivity provider Gogo, which also services global carriers including American Airlines, Delta, British Airways, Air Canada, Japan Airlines and Aer Lingus.

"Virgin Australia guests will soon be able to stay connected with their family, friends and colleagues on board," Virgin Australia Airlines group executive John Thomas said.

"We are confident that by working with Gogo and Optus Satellite and using their proven technology we can deliver the best possible and most reliable connectivity and entertainment experience in the air."

Qantas and Virgin have both said passengers will get connection speeds fast enough to stream video, and are backing that up by offering free trials on video on demand platforms Netflix and Stan.

Economy upgrade

Virgin has also launched a new fare category that will give economy passengers more leg room, their own overhead baggage storage and priority boarding and security screening.

All 75 of Virgin's 737 aircraft will be reconfigured to fit 24 to 30 Economy X seats, which will have at least 7.6 centimetres extra leg room and be located in the first three rows of the economy cabin and exit rows.

The new product will be free for Platinum Velocity frequent flyer members and cost $29 for other passengers, and will be available by the end of May.