Perth today became the first capital city in Australia to introduce free, blanket internet access in the central business district.

The city of Perth has spent the last two years setting up the WiFi system that allows people to move around the city with an uninterrupted internet connection on their mobile phone, laptop or tablet.

It sets Perth apart from other Australian capital cities in which users have to rely on hotspots in limited locations.

A series of hubs around the city extend the WiFi from Forrest Place, through the Hay and Murray Street malls and down to Barrack Square.

It has cost $300,000 to install with a further $150,000 set aside annually for improving services.

Perth's Lord Mayor Lisa Scaffidi says it is money well spent.

"This will definitely attract more people to the city," she said.

"It will encourage people to linger longer when they're in the city and certainly enjoy the freedom of the beautiful public space that we've created."

People using the service will be able to access the internet anywhere in the CBD for an hour at a time, before having to log in again.

Ms Scaffidi is hoping people accessing the free WiFi will use the service responsibly.

She dismissed concerns it could be used to anonymously conduct criminal activity, including downloading illegal pornography.

"They won't be able to download it as easily as people think," she said.

"This is going to be a service that I hope will be treated with responsibility and certainly used for the intended purpose."

Ms Scaffidi says there will be obvious benefits.

"Free public WiFi is a key economic driver that will further enhance and encourage business and enable visitors to enjoy their city experience even more," she said.

"We'll continue to expand this network over time to other key city precincts which will eventually include the Perth City Link area, Northbridge and East and West Perth."