Three major parks in Beijing have begun online ticket sales service ahead of the three-day holiday for International Workers' Day, authorities said Thursday.

From April till October, visitors to the Summer Palace, the Temple of Heaven and the Beijing Zoo can now buy tickets online, said the Beijing Municipal Administration Center of Parks in a statement.

A QR code will be swiped on their mobile phones at main gates, with no paper tickets required.

Wang Xiaojun with the administration said the trial run of the online ticket sales would save visitors from long queues and help parks handle the visitor in the peak season, especially during the holidays.

A total of 1.8 million tourists are expected to visit the city's parks during the holiday.

The service is expected to spread to all of the city's 11 parks and the Museum of Chinese Gardens and Landscape Architecture by the end of this year, Wang said.