Zillow has agreed to buy Trulia for $3.5 billion, both companies announced in a joint statement Monday.

The deal is expected to close in 2015 and was done in an all stock deal.

The two real estate websites will retain their names under the combined company. The websites offer vital information to homebuyers, renters and sellers looking at homes and rentals.

Trulia shareholders will get .444 Zillow shares for every share of Trulia they own. Reports last week from Bloomberg showed that Zillow was only seeking $2 billion for Trulia.

Mobile and online searches for homes and rentals are becoming much more popular. In June, Zillow reported 83 million unique users across their mobile and website platforms. That was a record for Zillow. Trulia also recorded record numbers in June, seeing 54 million unique users.

"Consumers love using Zillow and Trulia to find vital information about homes and connect with the best local real estate professionals," Zillow CEO Spencer Rascoff said. "Both companies have been enormously successful in creating compelling consumer brands and deep industry partnerships, but it's still early days in the world of real estate advertising on mobile and Web. This is a tremendous opportunity to combine our resources and achieve even more impressive innovation that will benefit consumers and the real estate industry."

Trulia and Zillow also helps real estate agents find new customers and prospective buyers. The two websites get revenue from advertisements and by charging fees to realtors for placing their homes and rentals on the sites.

At market close, Trulia shares were up over 15 percent and closed at $65.04. After being halted earlier in the day Zillow shares closed at $160.32 up about 1 percent.

There are some concerns over the companies merging. Some believe that fees charged to realtors will be increased and realtors will have to pay it because they'll have no alternative.

Have you ever used Trulia or Zillow to search for a new home or rental property? What was your experience like?