Google Inc. has launched in beta software that the company says will speed up the time it takes to search the Internet and to load web content.

Web Accelerator, which is available at no charge, runs alongside a browser and directs all searches and page requests through Google's servers. The software supports Microsoft Corp.'s Internet Explorer and the Mozilla Foundation's Firefox browsers.

In improving performance on the web, the application makes use of a cache, or data store, on the local computer, as well as caches on Google's servers, Marissa Mayer, director of consumer web products for Google, said Thursday. The software is only available for broadband users.

The desktop cache is for web pages that are pre-loaded based on a person's web activity. The software uses mathematical formulas to try to determine what web content the person is most likely to seek, based on prior behavior. The cache on Google's server is populated with popular web content based on the activity of Web Accelerator users as a whole.

Feeding web pages either from a desktop cache or a Google server is normally faster than getting the content from the public Internet. In addition, Google compresses the data for faster movement to the browser.

Google estimates that people who spend 20 hours to 30 hours a week on the Internet, could shave off about two to three hours a month in the time spent searching and loading web pages.

Privacy advocates, however, expressed concern over storing people's web browsing activities. Such information could be subpoenaed later by law enforcement agencies investigating criminal cases or by lawyers in civil cases.

"Google promises never to rent or sell the information to third parties, but it's still subject to handing over information through the subpoena process," Kurt Opsahl, staff lawyer at the Electronic Frontier Foundation, a privacy-rights group in San Francisco, said.

For consumers, the question is whether use of the software is worth the privacy risk, Opsahl said.

Under Google's privacy policies, the company does not track an individual's web activity, but does collect aggregated data from people using its services. Data collected from Web Accelerator users as a whole won't be used in Google's advertising services for now. The company, however, could decide to use it later.

"When you proxy your web surfing to Google, it does mean we will see the requests (for web pages and content)," Mayer said. "We have to, in order to optimize your web experience."

The software does not cache encrypted secure web pages, which, for example, are used in online banking sites and retail sites. The application also can be shut off, and users can clear its desktop cache at anytime.

Mayer argues that the benefits of the software outweigh any privacy risk.

"It's a product that can save you minutes everyday, and that adds up to hours over time," Mayer said.