The Home Depot website, www.homedepot.com, and the Lowe's website, www.lowes.com, offer the option to compare toolboxes sold at each store. Another resource to compare tool chests on wheels is bestcovery.com, which offers a buyer's guide for tool chests and a comparison of several top models of portable tool chests.
To compare portable tool chests on The Home Depot's website, pull down the Shop by Department tab on the left side of the homepage and choose the tab labeled Tools and Hardware. Choose "Portable Tool Boxes" for smaller tool boxes specifically designed for portability or choose Tool Chests for larger toolboxes, many of which do have wheels but are generally not meant for travel. Choosing either of these options pulls up a list of tool chests.
Above each picture is the option to compare toolboxes by clicking Select to Compare. Up to four tool chests may be compared at a time. The comparisons consist of reviews, availability, dimensions, price and other basic details. Lowe's offers similar comparisons by choosing the Shop tab located in the upper left of their website homepage, and then choosing Tools, followed by Tool Storage and Workbenches.
The Bestcovery website does not offer as large of a variety of tool chests to compare, but it does offer more comprehensive reviews and comparisons. The "Tool Chest Buyer's Guide" article, also on this page, offers advice on choosing the toolbox that is right for each individual and his needs.