Google is still the undisputed top dog in search, and has been for years. It commands about 65% of the U.S. search market, well ahead of competitors like Yahoo (YHOO) and Microsoft (MSFT). But that doesn’t mean it can afford to grow complacent. The Mountain View-based company consistently releases new search features in an effort to make its results faster, easier to look up and more relevant to users. After all, despite new products, search still accounts for an overwhelming percentage of Google’s revenues.

“If you give them [users] the information they want right away that’s why they would come back again and again to Google, which generates tremendous value,” Amit Singhal, Google fellow, said at a press conference the company held Tuesday morning in San Francisco to announce its new features.

Google’s new search by images function lets users copy and paste an image URL and drop it into the search box on the company’s homepage, or upload a picture directly from their computer. To search by voice on desktops, users will click on a microphone icon to the right of their search box, then speak their query out loud.

Other new features include Instant Pages, which Google says will open search results nearly instantly, a new user interface for tablet searches and a revamped mobile tool that lets users search by restaurants, coffeeshops or other local categories. But most of these new features will only be available to Chrome browser users, at least initially. And, despite recent speculation, Google didn’t announce any new social search features at its press event.

It’s no surprise that mobile in particular is the most attractive opportunity for Google and its search competitors. According to Google fellow Singhal, while desktop search traffic tends to dip during the winter holidays and summer vacation, mobile doesn’t experience a similar slump.

“It just keeps growing at an amazing pace,” said Singhal.

Singhal also said that relevance, simplicity and speed are fueling Google’s success in mobile. Those are the same key ingredients for the company’s lead in desktop search, which doesn’t seem to be diminishing anytime soon. Under new CEO Larry Page, Google is even more determined to better understand how, why, when and what users search.

“He [Page] wants us to know more rather than just find better,” Alan Eustace, Google’s senior VP of knowledge, said at the company’s press conference on Tuesday. “More broadly his view is that Google should be much better at understanding the world.”