Now they can pinpoint the areas where it happens.

The Free To Be interactive map being launched in Sydney on Tuesday by Plan International Australia lets women drop either a 'good' or a 'bad' pin detailing their experience of a particular spot.

New research commissioned by the NGO showed the majority of 452 women surveyed between the ages of 18-25 frequently experienced harassment on Sydney streets.

While PIA's head of advocacy Hayley Cull says it's hard to say whether street harassment is getting worse for young women in Australia, it certainly isn't getting any better.

"One of the impacts of how prevalent it is, girls are feeling desensitised to what's happening, they are starting to feel as though this is just normal and there is no point in reporting it," Ms Cull told AAP.

More than 90 per cent of women surveyed felt unsafe taking public transport at night, and nearly half said they also felt uncomfortable taking public transport alone during the day.

"We expected to hear about instances of street harassment in seedy laneways at night when it's dark and they're alone," Ms Cull said.

"What has been surprising is how common it is in broad daylight and areas where girls are just trying to get home from school or getting the train to work in the morning and are facing things like being groped or being leered at or being shouted at."

For 16-year-old Milly Grestle, her first memory of wolf-whistling was when she was in Year 4, and the public harassment has continued throughout her young life.

"I go to school in the city and I spend a lot of my hours working in the state library at night, it means I have to travel around the city alone," Milly told AAP.

"When I do I have to take precautions, so I'll have to call a friend or I'll text when I get home, or even sometimes not be able to go to the library after 8pm."

Since PIA launched its city safety map in Melbourne in 2016, more than 10,000 people have visited, dropping thousands of pins.

It's allowed its partners at Monash University XY lab to draw a clear picture of young women's experience around the streets of the city.

With the data revealing a high level of harassment on Melbourne's public transport, a phone app is now being developed for women to easily and quickly report any misconduct they witness or experience.

PIA will use the same concept for Sydney.

Australian Associated Press