The free-ranging Internet is under assault by mobile applications that connect people exclusively to content kept in "walled gardens" online, according to a US study released Thursday.

While 59 percent of the experts surveyed for the study felt that the Web would continue to thrive, they also thought "apps" for gadgets such as smartphones and tablets would power an "anti-Internet" used only to connect to services such as films or Facebook feeds instead of for open exploration.

"Instead of couch potatoes you'll have app potatoes," European Broadcasting Union head of institutional relations Giacomo Mazzone said in survey response.

"There will be again a digital divide. This one will be between those who will prefer to use ready-made applications and those who are building ways or searching on their own to find the needed solutions."

The Internet could give way to a hybrid model that combines open-ended quests for information or content with the use of "apps" tailored to plug efficiently into offerings hosted on online servers, survey respondents said.

"Tech experts generally believe the mobile revolution, the popularity of targeted apps, the monetization of online products and services, and innovations in cloud computing will drive Web evolution," the study said.

"Some survey respondents say while much may be gained, perhaps even more may be lost if the 'appification' of the Web comes to pass."

Slightly more than a thousand experts were surveyed for the Pew Research Center's Internet & American Life Project study that took a non-scientific look at how people will share and gather information online by the year 2020.

"Apps' ability to meet specific needs becomes a double-edged sword; they simplify life and create 'walled gardens' and a lack of serendipity," venture capitalist Richard Titus is quoted as saying in the survey.

"The Web is about discovery and serendipity, it's about finding something you weren't looking for... To lose that would be to take a step back in our progress as intellectual humans, the equivalent of burning a digital book."