"We ended 2012 with a strong quarter," Google co-founder and chief executive Larry Page said.
"We hit $50bn (£31bn) in revenues for the first time last year; not a bad achievement in just a decade and a half."
The fourth quarter profit was up 6.7% from a year earlier at $2.89bn (£1.8bn), and for the full year it grew 10% to $10.74bn (£6.8bn).
Revenue in the quarter that ended December 31 was up 36% from the same period a year earlier at $14.4bn (£9bn). For the year revenues grew to $50.2bn.
Google shares jumped more than 5% to $738.20 (£466) in after-market trading following the release of the earnings figures, which topped most Wall Street estimates.
Google dominates the US online advertising market, which grew 14.9% to $10.58bn in the final three months of last year, according to eMarketer.
The market tracker estimated that Google takes than 41% of digital ad revenue in the US and "holds more share than any other company" when it comes to online, display and mobile advertising.
However, cost-per-click prices were down 6% from the fourth quarter of 2011, and up 2% on the third quarter of 2012.
In a conference call with financial analysts, Google executives stressed how the company is connecting with people on smartphones and tablets, and cautioned that it would take time to get newly-acquired Motorola Mobility on course.
Mr Page said he was excited about the progress Google had made in handling search queries spoken to mobile devices, and described the online Play shop for music, books, applications and other digital content as "on fire".
Google's mapping service programme tailored for Apple (NasdaqGS: AAPL - news) gadgets running on the iOS platform had been a hit, Mr Page said, adding that its search and email programmes were also popular on Apple devices.
"We now live in a multi-screen world - in fact, we feel naked without our smartphones," Mr Page said.
"Devices have been one of our biggest bets in the last few years, along with the software that goes with these devices."
Google has been shedding unwanted Motorola Mobility assets since it completed its $12.5bn takeover of the company last year.
The move was seen as a grab for patents to protect Google's Android mobile operating system from legal attacks.
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