Pretty stable. My wife and I aren't the smallest people, big nordic boned tall people. I've had beds collapse on me before is what I'm saying. Not a problem with this bed. I was very hesitant and careful at first, and I'm sure if I stood and jumped on it, it might break the slats, but this bed has been very good for us! Assembly was a little rough as the bed came in three different shipments over the course of seven days, all with their own instruction sheet. So need to fill in some of the gaps yourself. Even so I had the bed assembled in less than an hour. You will want a drill as the frame itself is assembled with a hex wrench and bolts, but the slats screw in and there are no predrilled holes.