Websites around the world are preparing for the worst as Google prepares to change its search algorithm in order to change what is displayed on mobile browsers found on smartphones and tablets. The shift is expected to favor mobile-friendly websites and could potentially drastically alter where we shop and eat.

The new revised formula that is scheduled for release on Tuesday, will favor websites that are mobile-friendly, displaying them first and demoting sites that don't provide a mobile-friendly interface on smartphones and tablets. Although the new formula won't affect searches made from desktops and laptops, the new change could significantly influence how and where people spend their money when they look up locations from their mobile devices while they are on the go.

"Some sites are going to be in for a big surprise when they find a drastic change in the amount of people visiting them from mobile devices," CEO of website-building service Duda, Itai Sadan says.

It's probably the most significant change that Google Inc. has ever made to its mobile search rankings, according to Matt McGee, editor-in-chief for Search Engine Land, a trade publication that follows every tweak that the company makes to its closely guarded algorithms.

In order to stay in Google's good graces, websites must be designed so they load fast, look good and are easy to use on the smaller screened devices. Google has been urging websites to cater to mobile devices for years now, mainly due to the increase in searchers from mobile users. The number of mobile searches in the U.S. is rising by about 5 percent will searches from PC's have dropped slightly. In the final three months of last year, 29 percent of all U.S. searches, or 18.5 billion, were made from mobile devices.

While most major merchants and large companies already have websites that will cater to both traditional and mobile searchers, the new formula still threatens to hurt millions of small businesses that haven't had the financial resources or the incentive to make the necessary changes to their existing sites.

"A lot of small sites haven't really had a reason to be mobile friendly until now, and it's not going to be easy for them to make the changes," McGee says.

Unfortunately, the new algorithm may penalize some businesses that actually provide more relevant search answers compared to others simply because they are not mobile friendly.

That will be an unfortunate consequence, but also justifiable because a person might not even bother to look at sites that take a long time to open or difficult to read on mobile devices, Gartner analyst Whit Andrews said.

"Availability is part of relevancy," Andrews said. "A lot of people aren't going to think something is relevant if they can't get it to appear on their iPhone."