I don't know about "stackable", but they sure are sturdy.I had to order this twice. The first time the "set of 2" was a set of one. I called Amazon and they quickly sent a replacement. If you order this, be sure you receive two separate packages. There are not two in one package.These are better than similar ones I have had in the past. The rigid walls are a vast improvement over other models. This organizer doesn't collapse around the shoes. Also, the divider walls connect to the floor of the unit creating 12 distinct compartments. Each compartment is definitely only big enough to fit a single adult shoe, so each unit can hold six pairs of shoes. I much prefer this model which holds fewer shoes and actually gives my room the appearance of organization, to the last one I had that claimed to hold 12 PAIRS but wound up being nothing more than a plastic bag filled with shoes.I keep this under my bed so the sturdy handles have proved very useful, as does the clear top. I do wish that the hinged edge of the clear lid was one of the longer edges, but I can adapt.If I didn't keep this under my bed, the attractive sides would help it to blend in with the decor.In a nutshell, I love having a single home for my shoes rather than every room in the house. I save so much time every morning just knowing where to find my footwear. I think that this is a worthwhile purchase for anyone in the market for organizing supplies.My size 7 shoes fit in the cubes but for some clunky clogs. There is some height above each cube and the zippered lid. Therefore, I did stack some pairs one top the other and fit all but mentioned shoes in the organizer a pair to a cube without a lot of squishing. That said, I did sell shoes for a few years so know you have to play with positioning them to get them in the smaller spaces.The CARRY HANDLES WORK FOR SLIDING/POSITIONING BUT WILL NOT BEAR THE WEIGHT OF MANY SHOES. They just will not.Bigger, longer shoes than size 8/9 ladies will struggle to fit a pair in one cubby. I plan to use leftover space next to show or open cubby for off season socks and other small seasonal items.Knowing limitations this seems a good value for under bed storage.I bought two. Have only used one so far. I have plenty of shoes left but am downsizing to only what i can fit in these two under the bed storage bags. The second one will be boots and chunky heels. I will update once I see if that is gonna work. Overall I am satisfied. I needed some out of the way storage for my shoes. These fit great under my short bed frame. I feel like I got a lot of shoes in there. Might velcro some cardboard or something to the bottom to make it stiff. But I will most likely leave it on the floor when I am taking out or putting away shoes so it may not be a big problem.Read most of the reviews and they were accurate the outside frame is fairly solid just give it some time after you open it to uncrush. the dividers between each individual pair are soft and fabric but that makes sense because you couldn't fit in a small package without making them flexible. They still hold shoes just fine I typically wear a seven and a half but I had to have surgery on my foot and since then my foot has gotten bigger and I now wear an eight and a half and both sizes fit perfectly. Overall not surprised inadequate for shoe storage I don't need anything fancy just functional and that's exactly what it is.I ordered this product because it was the only one I found that would fit under my bed, and the price was very reasonable. However, although it does hold a good number of shoes (12 pairs), it doesn't seem to be constructed very well. Fortunately, it's the type of item that won't get a lot of use to cause wear and tear.These boxes are flimsy and can only be used flat on the floor. The handles are useful for pulling it out, but it needs to be full to easily push it under your bed. The compartments are a bit on the small side, width and height-wise. Anything over a standard dress shoe won't fit comfortably in there; you'd have to take up two spaces. Men's shoes wouldn't fit in these storage units.The deal on these shoe storage containers is great. I went to a box store and found one for the price of two of these. They were just what we were looking for. My only recommendation is that the storage slots be made a little larger. Both my wife and I had problems fitting our shoes without a lot of "stuffing" them in. Maybe in the future it would be worth considering making them larger. All in all a good deal and appear to be good quality.It’s all about creative storage when you live in a studio apartment. I had all this space under my bed, these fit easily. Booties fit but not mid or high boots. The material looks like it can take some slight wear, but for the price I’m happy with the purchase! Most shoes will fit a pair in each pocket, some shoes need a pocket for each shoe. I bought two pairs of these and I still have some room in each.