As expected, the click-and-collect or delivery trend is even more pronounced where stay-at-home orders are harshest and longest.

A national survey by leading comparison site Finder reveals a substantial number of Australians have changed their shopping habits over the past year.

It found 33 per cent of 1015 respondents or the equivalent of 6.4 million people have turned to buying groceries online, 43 per cent of them from NSW where Sydney has been locked down for nine weeks.

Some 31 per cent of Victorians are doing likewise.

The research indicates almost two in 10 Australians now make some purchases using a keyboard or tablet. Fourteen per cent make most of them that way and seven per cent are thinking of doing so.

"Online shopping has skyrocketed since the pandemic began and supermarkets have made significant changes to their in-store experience," according to personal finance expert Kate Browne.

"Many Australians now have a huge range of meal options at their fingertips, made even easier by food boxes, meal-kits and food delivery services."

Supermarket giant Woolworths has told AAP its weekly volume of online orders has doubled in NSW areas hit hardest by lockdowns and it is seeing a broader "significant uplift" across home delivery and click-and-collect services.

The chain has doubled its online order capacity in parts of Sydney, with many orders filled from dedicated warehouses in Lidcombe, Brookvale and Mascot.

"It's not often you'll hear a retailer urge customers to spend less time shopping but that's exactly what we all need to do right now," Woolworths Supermarkets Managing Director Natalie Davis said in a statement.

"If you need to visit a store, please be kind to each other and our team, sign in with the government QR code and, wherever possible, have just one household member do the shopping."

The supermarket said it is offering the first pick of its online delivery times to seniors, people with a disability or compromised immunity and those in mandatory isolation.

Despite the evidence of a broad shift to online shopping, the survey showed shoppers in lockdown-free Western Australia (78 per cent) and South Australia (70 per cent) still refer to go to the supermarket.

Baby Boomers (86 per cent) are least likely to have changed their habits, despite 82 per cent of them conceding it's more efficient to shop online.

Ms Browne recommends using online shopping as a money- and time-saving tool.

"It can give you the power to hunt around for a bargain," she said.

"Meal delivery services are great for those who have larger households looking to save money, cut down on food waste and spend less time shopping and cooking."

Australian Associated Press