This cart can help you move things up and down stairs.

I originally saw the first UpLift Cartat the National Hardware Show a few years ago, probably 2016. Since then they've introduced two newer models, one of which I showed on World News Now. It's the UpCart VersaTrolley. The company says it's significant because it is the most lightweight and compact cart in their product line, folding completely flat for easy storage. But yes,it's still capable of reducing effort while going up and down stairs or traversing rough terrain. This new UpCart folds to 4.5 inches flat and weighs in at 8 pounds and about 6 ounces according my postage scale. Even with its ability to be compactly stored it still offers a 77 pound weight capacity. But wait, there's more. It also comes with a custom-fitted bag to help transport anything from groceries to laundry. I like the fact that you can the bag off and use the handles to hold it, while you fold up the cart to ride public transportation. It's $79.99 and available June 2019. I was on the company website 3/19/19 and it's available for preorder for about $69.99, shipping in June. The lower price could end at time. Not shown but also new is the UpCart Lift which the company says is a powerhouse of a hand truck that’s light, easy to maneuver and readily hauls up to 200 lbs. over uneven surfaces. It’s the first folding hand truck to offer an all-terrain stair climbing chassis. Another  advantage is that it features the tallest handle in its class. That's great because most of the time the load your handling is a step below where you're standing and you won't have to bend over. This cart too folds flat in seconds for convenient storage. It's $99.99 and available now.  

Here's a longer Giz Wiz video of the two new UpCarts: https://youtu.be/32w89_Zehwc   

Company website: http://www.upcart.com/