You have more choices to choose the right mattresses online.
To determine the quality, look at the density and thickness of the foam, which will determine how deep you’ll sink. The newer, online mattresses generally use several different layers of foam, with heavier ones on the bottom for support and lighter, cooler kinds on the top for comfort.
They’re also recommended for lighter individuals as a harder mattress can end up not compressing for them at all. Softer mattress are generally better for those who sleep on their side, as they better cushion the shoulders and hips. On the side, a softer mattress better aligns the spine, too