SiteAdvisor is an extension to let you know of existing threats such as spyware, malware or viruses in web pages. SiteAdvisor’s engineers built a system of automated robots to test every Web site, download, and e-mail sign-up form on the Web.

Sites representing more than 95% of worldwide Web traffic have been tested for excessive pop-ups and other annoyances. So far we’ve tested. More than 475,000 downloads have been tested for viruses and bundled adware, spyware or other unwanted programs.

Sign-up forms are completed using a one-time use e-mail address so any subsequent spam can be tracked. Our bots receive mail from more than one million places already. Feedback from individual users and analysis by SiteAdvisor staff enhances SiteAdvisor’s automated testing. Site Report pages document every SiteAdvisor test.

As you search or browse, SiteAdvisor’s safety button changes color based on our test results to let you know:

Safe

We tested the site and didn’t find any significant problems.

Caution

Our tests revealed some issues you should know about. (Example: a site tried to change our browser defaults, or sent a lot of “non-spammy” e-mail)

Warning

Our tests revealed some serious issues that you’ll want to carefully consider before using this site at all. (Example: The site sent us lots of spammy e-mail or bundled adware with a download).