Backpackers are again proving their worth to the Australian tourism industry.

Latest findings from the Tourism Research Australia international visitor survey show that the number of young visitors rose a modest 2% last year.

But the good news was the 10% increase in spending during their stays, lifting it to an estimated $3.5 billion.

Australian Tourism Export Council managing director Matt Hingerty said today’s backpackers are tomorrow’s high-spending tourist families.

"Optimism is starting to rise across the tourism industry, and great results such as these are only going to fuel the enthusiasm of my members further," Mr Hingerty said.

While global travel fell by around four per cent last year, the survey showed that traffic into Australia remained steady, rising by 0.2 per cent.

Visitor nights and expenditure were both up more than five per cent, with strong rises in people visiting friends and family and for education.

A total 5.17 million people aged over 15 visited Australia last year.