High density foam is a very firm foam that generally makes up the bottom layer of popular memory foam mattresses. Other types of mattresses such as innerspring or hybrid may also use high density foam to support the spring systems.
High density foams generally are not used to create the entire mattress because they are just too firm. So, generally they are used as a foundation for the bed or to provide edge support.
High density foam is made of a blend of polyurethane and has a tendency to off-gas. If you are susceptible to lung issues, please do additional research on the quality of foams before purchasing.
Pros: Structural firm foam used by many mattresses to provide foundation and shape.
Cons: Off-gassing problems with lower quality foams and it is too firm to make a mattress in its entirety.
A pillow top is a surface layer of soft material that is stitched and packed into the cover. This provides a soft as a cloud feel to the surface of the mattress.
There are multiple types of pillow tops, though the most popular recently is a memory foam pillow top. A memory foam pillow top has a thin layer of soft memory foam that is stitched into the cover. Though memory foam is a popular material for pillow tops, you can also find them with latex, cotton, cashmere, wool, or goose down/feathers.
Pillow top mattresses generally have spring support systems in the middle of the mattress, though there could be a pillow top on a memory foam mattress as well (it is just not very common).
Pros: A plush feel on the top of the mattress that pillows the body on top of the support layers.
Cons: The pillow top alone will not make a good bed -- the materials used in the pillow top and the rest of the mattress can sag or have issues if they are lower quality.
Overall Score:
High Density Foam: 8.9/10
Pillow Top: 8.9/10
Comfort:
High Density Foam: 8/10
Pillow Top: 9/10
Softness:
High Density Foam: 7.5/10
Pillow Top: 9.4/10
Cooling:
High Density Foam: 8/10
Pillow Top: 8.2/10
Hypoallergenic:
High Density Foam: 8.1/10
Pillow Top: 8.5/10
Odor:
High Density Foam: 8.4/10
Pillow Top: 8.8/10
General Support:
High Density Foam: 8/10
Pillow Top: 8.2/10
Eco-Conscious:
High Density Foam: 8.5/10
Pillow Top: 8.5/10
Price Value:
High Density Foam: 9.4/10
Pillow Top: 8.2/10