From shoes to jeans to little black dresses, there’s no substitute for trying on clothes before you buy. But if you want to skip cramped dressing rooms and crowds and shop online, Consumer Reports ShopSmart says some online retailers have developed brand-new tools that help you pick the right size.

Consumer Reports’ favorite tool is True Fit. It’s easy to use. You don’t have to do any measuring. You answer a couple of questions, and it recommends a size for you. And it also gives you fit tips about how the garment will fit your body. True Fit is available on 15 retailers’ sites, including Nordstrom and Lord & Taylor. Some other online retailers are also trying out fitting tools.

Dressipi is a useful tool Consumer Reports ShopSmart looked at that works on Apple devices. You plug in the size you wear in your favorite brand, and the app will tell you the best size in more than 500 other brands.

As for shoes? The tool Shoefitr helps you compare sizes among hundreds of brands and styles. Consumer Reports likes that it does a scan of pairs of shoes so that it has a really good, almost like a 3D replica of the shoe. So it can tell you if you wear a size 8 in this particular shoe, maybe you need a 7½ in that shoe.

When it comes to jeans, Levi’s’ website offers a quiz so that you can ID your curve and find the best fit.

There’s also a space-age tool available in a few Bloomingdale’s stores. A scanner like hose used in airport security takes precise measurements of your body, then gives you the right sizes and best fits in dozens of brands. It’s like an instant custom fitting and personal buyer all in one.