In about two weeks, Google plans to make a major change to the algorithm for its mobile search, giving mobile-friendly websites a higher position in search rankings.

For a company that dominates the search market with an approximately 75% share, this is going to mark a significant change for mobile search.

"I think it should be a shake-up for mobile," said Collin Colburn, an analyst with Forrester. "Google does change its algorithm quite frequently, but this is a bit of a larger change.... Websites that are not designed [with mobile in mind] will take a hit and websites that are responsively designed will begin to rise in search results."

He also noted that the change should mean that consumers will have a better user experience because they'll be directed to more mobile-friendly sites.

In a February blog post, Google noted that the company's search team is focused on making its service better for the burgeoning base of mobile users.

"When it comes to search on mobile devices, users should get the most relevant and timely results, no matter if the information lives on mobile-friendly web pages or apps," the company noted. "As more people use mobile devices to access the Internet, our algorithms have to adapt to these usage patterns."

That algorithm change goes into effect April 21, affecting mobile searches in all languages worldwide.

Google warned that the change will have a "significant impact in our search results" and offered up a link website operators can use to see if their site is considered mobile friendly.

Google did not specify in its blog post, and would not comment on, what exactly is being changed in its mobile search algorithm -- the software processes and formulas used to cull through the Internet to find what the user is seeking.

The company did say the new algorithm will expand its use of "mobile-friendliness" as a ranking signal. "Consequently, users will find it easier to get relevant, high quality search results that are optimized for their devices," Google noted in its blog.

That should be a good change for users, according to Dan Olds, an analyst with The Gabriel Consulting Group.

"The problem is that not every website is configured to be mobile friendly," he added. "Some are set up to be way too large for a mobile screen or too difficult to navigate. With this announcement, Google is saying that when they sense that a mobile user is running a search, they're going to rank sites that are mobile device optimized above others."

That will change what mobile users see at the top of their search results because it also will affect websites that either drastically move up or down in those result rankings.

"This could dramatically change search results in some cases," said Olds. "It might allow a mobile-optimized second-tier player to get a jump on larger competitors who have not configured their site for mobile yet. We'll probably hear about specific cases as the new algorithm comes into broad usage."

It's all about reward and punishment for websites, according to Karsten Weide, an analyst with IDC. For websites that have been optimized for mobile devices, this will be a great change. For sites that have not, it's bad news.

Most mobile users will not notice an obvious change, she added, but it will be a big deal for Google itself. "It should give [Google] better performance for ever more frequent mobile users, therefore more traffic and therefore more ad sales," Weide explained.

Forrester's Colburn foresees a boost for Google, which is getting increased competition from the likes of Yahoo and Bing in the search market.

"More and more consumers search via mobile," he said. "With around 40% of the world's population owning a smartphone, mobile search is becoming increasingly popular with consumers on the go. So [Google] needs to constantly be changing its algorithm to provide the best and most useful searches that consumers need."