Somnero buying guidance
Types of mattress: foam, coil, hybrid
Originally published September 19, 2026.
Almost every mattress on the market falls into one of three categories: foam, coil or hybrid. The difference between them is not quality — it is behavior. A bad mattress of each type is equally bad; a good mattress of each type is right for someone else.
Foam
A block of foam layers, usually memory foam over a high-density polyurethane base. It contours to the body and isolates movement well: if you sleep with someone who turns over a lot, this is where you notice it. The trade-off is airflow — foam holds heat longer than coils do, and cheap layers develop a permanent dip within two or three years.
What to ask before buying: the density of each layer. Below about 1.8 lb per cubic foot in the base layer, the mattress will not last. If the seller does not know the figure, they have not read the spec sheet.
Coil
A coil core, today almost always individually pocketed coils. The surface feels firmer on contact and cooler, because air moves through the core. It is easier to get out of in the morning — which matters if mobility is an issue.
What to ask: the coil count for that size, and whether they are pocketed. Connected Bonnell units pass movement across the whole mattress and are a sign of cheap construction, however thick the comfort layer on top.
Hybrid
A pocketed coil core with foam layers above. It tries to take the airflow and support from the coils and the contouring from the foam. It works, and it is also the easiest type to hide weak construction in: an inch of good foam over a cheap core sells as ‘premium hybrid’.
What to ask: the thickness of the comfort layer and its density, separately from the total height. A twelve-inch mattress where ten inches are coils and two are low-density foam is not better than a nine-inch one built honestly.
How to choose between them
You sleep on your side and your partner wakes you: foam, or a hybrid with a thick comfort layer. You sleep hot, or you are over 220 pounds: coil or hybrid. You have lower-back pain and sleep on your back: firmness matters more than type. In every case the trial at home decides — ten minutes in a store tells you nothing about the thirtieth night.
What does not matter
The number of layers listed on the product page. A manufacturer can count the cover, the knit, a layer of adhesive and a film as four ‘technology layers’. What matters is what each one does and how long it lasts.