Walmart expands online savings tool across the U.S.

Walmart is expanding its online tool that compares prices on thousands of products with those of some of its competitors to cities nationwide in the next few months.

The world's largest retailer also plans to offer thousands more products, from general merchandise like TVs to produce, on the online tool that's called Savings Catcher.

Walmart rolled out Savings Catcher in seven markets in March, allowing customers to compare prices of 80,000 grocery and household products. If the tool finds a lower price elsewhere, it refunds the difference to shoppers in the form of a store credit.

Rivals have been offering to match the lower prices of competitors, but only if shoppers do the research on their own. Savings Catcher is designed to do the legwork for customers.