Digital media isn’t getting any younger, but it is certainly getting more useful, according to Nielsen.

The research firm on Monday highlighted some of the year’s biggest trends in Web and mobile usage.

Most notably, computer-based Web activity has declined among all of the top 10 U.S. sites, including Google, Facebook, YouTube, Amazon, and Wikipedia.

The Ask Search Network, Facebook, and YouTube took the biggest hits, all reporting year-over-year percentage drops of 14 to 18 percent, compared to Amazon and MSN/WindowsLive/Bing, which saw a waning of only 1 to 2 percent.

Throughout the year, the 10 most popular Web brands garnered a total average of 1.05 trillion unique U.S. visitors each month — an 85 percent year-over-year drop since 2012.

But as consumers shift from PC-based browsers to mobile and tablet screens, they can’t seem to kick the habit of watching grown adults sing and dance in forest animal costumes on the Web.

Online video viewing continued to grow, Nielsen said, with YouTube as the top source for streaming — again — as 128 million Americans viewed video content on the site each month. Vevo, The CollegeHumor Network, Hulu, and Netflix also made the top 10.

This continuing rollover to mobile devices has helped push smartphone penetration up from 56 percent at the start of the year to 65 percent by October.

And while it’s no surprise that a majority of the nation carries an iOS or Android-based smartphone (93 percent combined), mobile app use is at a surprising high among users 18 years and older.

According to Nielsen, Facebook remained the most-used smartphone app across either platform, with more than 103 million unique visitors each month — a 27 percent boost from 2012. Instagram and Apple Maps, meanwhile, took home the largest gains, jumping 66 percent and 64 percent, respectively, over last year.

Google Search, Play, Maps, and Mail also boasted big numbers, as well as the mobile versions of YouTube, Stocks, and Twitter, which rounded out the list with 30.7 million monthly users.