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Michael is a professional writer based in Boston and someone who has always been fascinated with the mysteries of sleep. When he’s not reading about new sleep studies and working on our news section, you can find him playing video games or visiting local comic book stores.

Casper vs. Amerisleep Mattress Comparison

The Casper and AS3 have the same firmness, with the same benefits of body conforming and motion isolation, but their distinctions are what’s going to tell you which one, if any, is suitable for you. Hopefully, this will make it easier for you to navigate through the options and choose a bed to your fitting.

Casper and Amerisleep are two of the leading companies in the bed industry. Casper is the newer, founded in 2014. Its flagship mattress, the Casper mattress, is made with a triple-layer comfort system from memory foam and polyfoam, along with a support core layer from high-dense polyfoam. In terms of firmness, the Casper is a 5.5 on the 1-10 scale, classified as a medium firm.

Amerisleep was first launched in 2007. Its flagship model, the Liberty, currently known as AS3 mattress, holds a spot in the company’s memory foam mattress line in offer. This bed consists of a two-part polyfoam base, a comfort layer from memory foam, and a cover made of Celliant fabric, spandex, and polyester. Much like the Casper, it ranks as 5.5 on the firmness scale, and it is a medium firm bed.

It is well worth mentioning that both Casper and Amerisleep offer other models along with the ones just mentioned. Casper also created the Casper Essential and the Casper Wave – the first one is memory foam, and the latter is memory foam and latex model. Amerisleep, besides the AS3, has four more memory foam models, primarily different in firmness: AS1 (7.5), AS2 (6.5), AS4 (4.5) and AS5 (3.5).

The similarity of the brands’ flagship models is what makes them the focus of this article, as you are more likely to have difficulties choosing between two slightly different mattresses than the completely different ones. The Casper and AS3 have the same firmness, with the same benefits of body conforming and motion isolation, but their distinctions are what’s going to tell you which one, if any, is suitable for you. Hopefully, this will make it easier for you to navigate through the options and choose a bed to your fitting.

The Casper

This model has three comfort layers – it is a polyfoam sandwich with memory foam in the middle. It creates a moderately firm surface and provides close conformity to the sleeper. The base, made entirely of highly dense polyfoam, ensures the surface is even and the bed supportive. The mattress is covered by a case that is 100% polyester. The 9 ½ inches thickness of this bed makes it slightly shorter than average, but with only 71 pounds of weight, it is one of the most lightweight designs available, even compared to all-foam ones. The Casper is fairly easy to lift and move around as you please.


AS3 is made of memory foam, with a 4 PCF foam comfort layer that is three inches thick and wrapped into a cover from polyester and Celliant fabric. As a result, the bed conforms closely to the sleeper’s body but stays cool much better than the memory foam standard. The base of this model is quite thick, with two inches of polyfoam as a transitional layer and the surprising seven inches of higher density polyfoam as a core. Without doubt, this support system strongly reinforces the bed, keeping it flat and forgiving a lot of near-edge sitting. The AS3 is a bit heavier than the standard with 88 pounds, limiting the rotation and moving of the bed, but with a base as thick as nine inches, that is to be expected.


The Casper has been reported as highly durable by owners, but since the company has only been present since 2014, it’s too soon to tell how long the mattress will last. The formal assessment will have to be “so far so good” until further notice.

AS3, however, has been around for longer and its durability is, safe to say, a bit below the average of memory foam. This doesn’t mean it’s going to become useless after a few years – the average lifespan of memory foam is seven years, so the AS3 might still be in shape for at least five, which is quite good compared to other types of beds.

Temperature Regulation

The score for both competitors is good, but not great. The Casper tends to absorb minimal body heat and remains relatively fresh during the entire night, but if sleeping hot is a persistent struggle for you, that might not be enough.

Similarly, due to the Celliant fabric in its cover, AS3 offers relatively stable temperature neutrality throughout one’s sleep, which is as good as you can expect from a memory foam mattress.

Motion Isolation

This is one of the strong suits for both the Casper and AS3. The ability to keep the rest of your bed almost completely still while your partner may be tossing and turning, or getting up during the night, recommends both of these models to couples. Owners’ reports came back positive on this one.

Body Conforming

The Casper conforms closely to the sleeper’s body, making it excellent for people who regularly experience back or neck problems, along with stress in pressure points – depending on your preferred sleeping style, these may be in the hips and shoulders (side sleepers), lower back (back sleepers) or your limbs (in stomach sleepers).

The AS3 has this quality as well. Targeted pressure and pain relief are to be expected when sleeping on such a conforming mattress in any position or combination of positions. This goes for owners of any weight.


With the AS3, smaller off-gassing issues have been reported among customers. The odor is easily aired out in a matter of days. The Casper scores a tad lower here, with more reports of off-putting smell coming from the newly bought bed. However, as with the AS3, it will dissipate quickly.

Edge Support

The Casper isn’t ideal in this category. With the minimal support around the edges, it earns a passing grade, but sinking over time is very likely – and that’s even worse keeping in mind it’s only been around for a shorter while.

The AS3, contrarily, includes this quality as one of its advantages, as its strong support in the base keeps it very durable around the perimeter. With this model, you are sure to avoid a significant amount of indentation, keeping the bed’s entire surface flat almost for as long as you have it.


Neither model makes a good fit in this category. Responsiveness or bounciness is what’s generally wanted for sex, and memory foam types usually aren’t the best candidates, not with their conformity and motion isolation. If this is an essential factor for you, better seek a different option.


Exposure to loud environmental noise is known to disrupt sleep. For many individuals, even the sounds that some beds make have the ability to wake them up as they switch positions during sleep. The noise category is where both the Casper and AS3 excel. With the solid foam structure and their medium firmness, these models are practically silent while bearing weight. This is another of the factors commonly sought after by couples, particularly those who are highly sensitive to sounds and wake up easily. If you are one such individual, or perhaps your partner is, choosing any of these beds would be a safe pick.

Trial Periods, Warranty and Delivery

Both the Casper and Amerisleep have 100-night long trial periods and the possibility of a full refund. The warranty is two times longer for the AS3, and the shipping is different, too. Below are the general rules for both models in a bit more detail.

The Casper

The AS3

Sizes and Prices

These mattresses fall into the average when it comes to pricing. The Twin size, available in both models, comes cheaper in the Casper, costing $695 compared to AS3’s $899. As the sizes go up, however, the prices even out, all the way to California King, which is $1495 for the Casper, and $1499 for the AS3.

Final Verdict

The Casper may be good for you if:

Reconsider in case you weigh more than 230 pounds, you want a higher-profile bed, or you are looking for a mattress that is more firm and less conforming.

The AS3 may suit you if:

Skip this one in case you like lower-profile beds, want a less conforming or more firm mattress.

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