Jessica Biel vs. Kim Kardashian: Who Has the Best Butt?

Jessica Biel and Kim Kardashian Credit: Mark Sullivan/WireImage.com; George Pimentel/WireImage.com

In the battle of the A-list backsides, Kim Kardashian can't be beat!

According to new search data released by Bing.com, 21 percent of site users searched for information related to the 31-year-old Keeping Up With the Kardashians star's derriere and her workout routine as they prepped for summer bikini season.

VIDEO: Watch Kim Kardashian get a butt X-ray

Coming in second was none other than Jennifer Lopez, 42, with the American Idol judge and mom of 4-year-old twins' bootylicious behind accounting for 13 percent of all search traffic over the last three months.

Jessica Biel -- who showed off her toned bikini bod June 22 on vacation in Puerto Rico -- was the third most searched celebrity, with users clamoring to know more about how the future Mrs. Justin Timberlake scored her slammin' derriere.

PHOTOS: Jessica Biel's hottest, most revealing body moments

How does the 30-year-old Total Recall actress keep her body in tip-top shape? "For me, getting enough sleep, drinking lots of water, having a healthy diet, and staying away from alcohol are musts," she told ELLE in June 2011. "It's so boring, I! know, b ut doing those things really helps."

Jessica Biel and Kim KardashianCredit: FameFlynet; Brian Prahl/Splash News Online

As bikini season gets into full swing, users are also hitting up Bing.com for info on how to tone their arms and abs.

PHOTOS: Easy at-home moves to score sexy abs

Coming as no surprise, 53-year-old Madonna topped the arms category, with her toned muscles yielding 36 percent of all user-initiated body related searches from March through May 2012. Black Eyed Peas' Fergie, 37, earned top honors for her enviable abs, having garnered 67 percent of Bing's search traffic.