New self-service machines that are on trial at Changi Airport's Terminal 2 are letting travellers breeze through the boarding gates in under three seconds.

The do-it-yourself option is part of a bigger push by the airport for automation to boost productivity amid a tight labour market.

With the three automated kiosks at Gate E8, airport staff are no longer needed to do manual checks. All travellers have to do is scan their boarding passes to open the gate. From there, it is straight into the aircraft.

But security screening, as well as checks on prohibited items such as excessive amounts of liquids and gels, are still done before entry into the gatehold room, said Changi Airport Group's vice-president (terminal and ground operations) Albert Lim.

Since the machines, which cost $75,000 each, were installed in May as part of a tie-up with German carrier Lufthansa, the total boarding time has been cut and the response from users has been positive, he said.

The airport is in talks with other carriers and will progressively provide more of such machines across the three terminals in the coming months, Mr Lim added.