The study by the Pew Internet & American Life Project to be released on Thursday finds men are slightly more intense users of the web.
Men log on more frequently and spend more time online. More men also have access to quick broadband connections than do women.
Deborah Fallows, a research fellow at Pew and author of the report, said: "Once you get past the commonalities, men tend to be attracted to online activities that are far more action-oriented, while women tend to value things involving relationships or human connections."
A larger number of men surf the internet for pleasure, with 70% acknowledging they go online to pass time, compared with 63% of women.
Men are more likely than women to listen to music, view webcams and pay for digital content.
But women are catching up in several areas measured by the survey, and intensive use by younger women suggests some of the gaps will continue to narrow.
Already, women are heavier users of email, often going beyond the matter-of-fact responses of male correspondents to use email to share stories, solve issues and reach out to a wider network of friends and family.
Both genders look to the web as a font of information and as an efficient communications tool, said Fallows.
Women use email to solve issues
and reach out to family, friends
Overall, the percentage of men and women who use the web are nearly equal.
Roughly 68% of men and 66% of women report making use of the web, up from 20% of the US population Pew found in 1995, when men made up 58% of the online audience.
Over the past decade, men have proved more willing to engage in riskier encounters or transactions, such as joining chatrooms, bidding in online auctions or trading stocks.
Auctions attract 30% of men versus 18% of women.
In addition, 21% of males confess to looking at porn online compared with just 5% of females, the Pew survey has found.
This area is difficult to measure and may be underreported by survey respondents, Fallows said.
Meanwhile, 74% of women seek health or medical information online, far more than the 58% of men who do so.
Thirty-four per cent of women seek religious information from the web versus 25% of men.
Such differences mirror gender differences in the offline world, Fallows noted. Men go online more frequently, as 44% use the web several times daily versus 39% of women.
Men are more likely to be aware
of the latest technology jargon
Partly this reflects their greater broadband access, requiring less time to wait for dial-up connections.
Seventy-eight per cent of men have broadband connections at work versus 69% of women, although the broadband gender gap narrows among both sexes at home.
In addition, the survey found men feel more in control of their computers.
Far more men fix their own computers, for instance. Men also are more likely to be aware of the latest technology jargon - terms such as spam, firewall, spyware, hardware, phishing and RSS.
Based on responses by thousands of US web users to a questionnaire covering 90 areas of online activity, the Pew report finds some of the gender differences to be generational.
Girls and young women are more facile with technology-intensive activities than older generations of women appear to be.
Eighty-six per cent of women aged 18 to 29 are web users, compared with 80% of men. But 34% of men 65 and older use the internet, compared with 21% of elderly women.
"Teenage girls may do more or less than boys of certain activities, like downloading, but the important message is that the technology is not standing in their way"
By 2004, 22% of teenage girls had started a blog, or online journal, versus 17% of boys.
Yet boys are far more likely to download music or videos, with 38% of boys saying they watch online video versus 24% of girls.
"Teenage girls may do more or less than boys of certain activities, like downloading, but the important message is that the technology is not standing in their way," the report states.
As younger women grow up, women are likely to overtake men in terms of the overall audience, Fallows predicts.
The report cites data from surveys performed by Pew from 2000 through 2005. Some 6403 respondents took part in 2005.