This loosely defined category combines elements of spring and foam construction in the core. This is different to a typical mattress where the foam or spring core provides most of the support and foam layers are added for comfort.
Because there's no real hybrid mattress standard, you'll find a wide variety of models that claim to be hybrids. We apply the term when the foam and spring components provide equal levels of support, rather than just a comfort topper.
Key differences between foam and spring mattresses
Manufacturers often claim that certain sleepers and body types are better suited to spring or foam mattresses. But there aren't any consistent results in our tests that indicate whether one type is more suitable than the other.
The best option is mostly a matter of personal preference towards the general 'feel'. Though there may be theoretical rules about how foam and springs differ, the build quality plays a significant role that ultimately determines how the mattress feels to you.
Our tests assess comfort and support in dorsal (back) and lateral (side) position. Until recently, this was conducted with people chosen to comply with the 5th percentile female (1.55m/54kg) and the 95th percentile male (1.91m/104kg).
We have since switched to dummies that comply to female (1.55m/55kg) and male (1.9m/100kg) heights and weights. This range covers 90% of the general population and are similar enough to allow our current results to be comparable with previous tests.
We haven't tested models that are advertised as being predominately memory foam and cannot comment on how those results compare to standard and HR polyurethane mattresses.
Comfort, support and comfort retention
An equal percentage of foam and spring mattresses showed good, average and poor performance in these tests. To put it simply, there's a lot more that goes into support and comfort beyond 'foam versus spring'.
The best example of this are results for two Koala mattresses in our initial comfort tests – the Koala Mattress (2021 model) and the Calm As Mattress. The Calm As scored an average of 69% in the dorsal test and 56% in the lateral, while the standard Mattress scored 58% and 48% respectively.
They should be in the same ballpark due to the standard polyurethane foam cores used, if marketing is to be believed – but that's not the case. It's likely the different layering of various thicknesses of foams makes more of a difference.
Spring mattresses are also inconsistent. For example, the A.H. Beard King Koil Comfort Plus scored 59% and 49% while the Slumberland Sutton Pillowtop scored 72% and 57% in back and side sleeping positions respectively.
Foam mattresses are often marketed as the more stable, less bouncy option but our stability test says otherwise. About half of both the currently available spring and foam models in our test earned a score of 60% or higher. The highest rating models for stability were all pocket spring mattresses. However, Bonnell and light spring mattresses rated poorly.
This is one of the only areas with notable differences between foam and spring mattresses. Our tests measure the insulation to determine mattress warmth and the amount of sweat that's retained during a night's sleep.
A foam mattress is kind of a big sponge, if you think about it, so it makes sense that airflow isn't as good compared to a spring model. We found that more spring mattresses had a cool or very cool feel compared to the polyurethane foam models.
However, the two latex mattresses in our test were also cooler feeling, but still collected a lot of sweat. The spring models did a better job of repelling sweat, including two models that earned perfect results.
How long do they last?
Our usage, wear and damage tests simulate eight years of use, which is the standard life expectancy for a good quality mattress. Comfort retention results – aka how similar the mattress feels after eight years compared to day one – were consistent across the different types.
There's an even spread of good, average and poor performers in all types in our test. However, there are fewer foam mattresses with notable sagging.
Foam mattresses may not last as long if you're prone to sweating due to a warmer climate or health reasons. Sweat absorption can damage the mattress over time and cause odours, so you may want to consider a spring model in this instance.