Shoppers turn to mobile devices for fashion shopping and buying.

Back-to-school shopping is a high-volume shopping event that is second only to the holidays; but unlike the holidays, shoppers are planning their journeys even earlier.

That’s one of the key findings from Google’s back-to-school trend report, which looked at how people are using Google Search and YouTube to inform their shopping trips.

The results were included today in a post from Google’s Lisa Gevelber, who shared trends and habits in what is estimated by the National Retail Federation to be a $75.8 billion shopping season.

This year, Gevelber wrote, back-to-school-related search queries began a week earlier than last year, with a sharp rise during the week of July 11.

As is consistent with shopping trends overall, mobile devices and videos played a bigger role this year. In July, three out of five back-to-school-related searches were on mobile devices; mobile searches were up 35 percent compared with last year. Gevelber also reported that there was “strong evidence that searching actually leads to store visits,” citing research that last August, back-to-school searches that were followed by a department store visit within a week had grown 20 percent.

Back-to-school videos on YouTube were up more than 70 percent, with a focus on topics such as DIY and dorm tours, and 85 percent of those views were on a mobile device.

As far as trends, Google looked at back-to-school items such as backpacks, shoes and school supplies. It found that the top trending backpacks were Victoria’s Secret PINK, which had a 1,000 percent spike in search interest. Other top backpack brands were Sprayground, Fjallraven, Kavu and Pokemon-themed backpacks. The report also noted that retailers should be mindful of regional differences in search terms. For example, the word “bookbag,” an alternative word for backpack, was up 300 percent and was popular in states such as South Carolina, North Carolina, Georgia and Delaware.

In shoes, Birkenstock continued their reign as the top choice, with interest up 46 percent this year. Other popular shoes on Google were Under Armour’s shoes created for basketball player Stephen Curry and Kanye West’s Adidas Yeezy Boost. For school supplies, the brand Yoobi was “hot,” with search interest doubling since last July.

Although the heat of back-to-school season has subsided a bit this season, Google did say that a “second wave” of shopping happens after winter break, as January back-to-school searches have been stronger every year since 2013, Google said.