So you’re comparing the Casper and Amerisleep memory foam mattresses? Good choices. Both of these mattress models are all-foam beds made with high-quality materials and unique comfort technologies. But which is right for you? That’s what we’ll talk about in this mattress comparison.
Learn about how bed-in-a-box companies Casper and Amerisleep differ in this review.
Highlights and An Overview
Customer Rating
MA Score
Summary
Firmness
Type
Trial Period
Warranty
Customer Rating
MA Score
9.1/10
Summary
Universal firmness mattress for the average sleeper
Firmness
Medium-firm: 6/10
Type
Memory foam
Trial Period
100 days
Warranty
10-year limited warranty
Customer Rating
MA Score
8.4/10
Summary
Memory foam mattress with cooling technology (part of Amerisleep's Soft Collection)
Firmness
Medium: 6/10
Type
Memory foam
Trial Period
100 days
Warranty
20-year limited warranty


Casper
Amerisleep AS3
Customer Rating
MA Score
9.1/10
8.4/10
Summary
Universal firmness mattress for the average sleeper
Memory foam mattress with cooling technology (part of Amerisleep's Soft Collection)
Firmness
Medium-firm: 6/10
Medium: 6/10
Type
Memory foam
Memory foam
Trial Period
100 days
100 days
Warranty
10-year limited warranty
20-year limited warranty
Key Similarities
- Both are medium-firm mattresses. This is the ideal firmness option for the average sleeper or for shoppers who want a mattress with broad appeal.
- The Casper and AS3 are all-foam beds with memory foam layers and cooling features.
- You get 100 days to trial both of these mattresses.
- Both beds scored well when tested for spinal alignment and motion transfer.
Key Differences
- Casper gives you a 10-year limited warranty, while Amerisleep gives you double that with a 20-year limited warranty.
- Casper is significantly more budget-conscious than Amerisleep.
- Casper scored higher for pressure relief and edge support, while Amerisleep received better scores for cooling and durability.

Casper Mattress Review Highlights
- Targeted Support: Casper’s comfort layer features Zoned Support™. That’s their trademarked way of saying that you’ll experience the right amount of firmness for each region of your body.
- Top-Rated for Side Sleepers: The Casper mattress is a tested and true top pick for side sleepers. It scored remarkably high for pressure relief and spinal alignment, both of which are important categories for side sleepers.
- Responsive: Casper is also a slam dunk for combo sleepers. It scored 10/10 in our responsiveness assessment.
- Broad Appeal: Mattresses with a medium to medium-firm feel are comfortable for most sleeping positions. Casper is 6/10, or medium-firm, on the firmness scale, which has a comfy blend of contouring and support for back sleepers, stomach sleepers, and side sleepers alike.
- Breathable: Casper designers wanted a cooler mattress than traditional memory foam, so they added tiny holes in the foam to allow your body heat to flow away.
- You can also see if the Casper Element, Casper Hybrid, Casper Nova Hybrid, or Casper Wave Hybrid may be better for you.

Amerisleep Mattress Review Highlights
- Motion Transfer: The foam layers absorb motion from movement before they affect the rest of the mattress surface. This is a feature that couples look for, since motion isolation reduces sleep disruptions.
- Cooling: The AS3 mattress features Amerisleep’s Bio-Pur® material, which is designed to keep you cool with an open-cell structure.
- Eco-Friendly: The Bio-Pur memory foam is made with renewable plant-based oils and way fewer petrochemicals than traditional memory foam. It’s also CertiPUR-US® certified, which is better for your family and the planet because there is less off-gassing in the environment and your home.
- HIVE Technology: The AS3 transition layer is constructed with Amerisleep’s HIVE technology, which keeps your spine aligned, reduces stress on pressure points, and creates a sleeping-on-clouds feel.
- 20-Year Warranty: You have 2 decades with your Amerisleep mattress before it’s out of warranty, while most mattresses’ peak performance years happen in the first decade.
- For various firmness levels, check out the AS1, AS2, AS4, and AS5.
Mattress Sizes
Casper and Amerisleep have almost identical dimensions, but Amerisleep’s Twin is 1” shorter.
Casper |
Amerisleep |
|
Thickness | 11″ | 12″ |
Twin Size | 39″ x 75″ | 38″ x 74″ |
Twin XL | 39″ x 80″ | 38″ x 80″ |
Full Size | 54″ x 75″ | 54″ x 75″ |
Queen Size | 60″ x 80″ | 60″ x 80″ |
King Size | 76″ x 80″ | 76″ x 80″ |
Cal King Size | 72″ x 84″ | 72″ x 84″ |
Learn more about mattress sizes.
Mattress Prices
Casper is decidedly the more budget-friendly mattress. Compare both brands’ prices by size below.
Casper |
Amerisleep |
|
Twin | $626 | $1,099 |
Twin XL | $795 | $1,149 |
Full | $995 | $1,249 |
Queen | $1,095 | $1,399 |
King | $1,495 | $1,699 |
Cal King | $1,495 | $1,699 |
Compare What’s Inside
These two different mattresses actually have a lot in common. Take a look inside to see how the all-foam layers stack up.

Inside The Casper Mattress
- Soft Cover: Casper makes their soft polyester cover from up to 57 recycled bottles.
- Airscape™ Foam: This is the softest layer on the Casper mattress. It’s made of polyfoam, which is a little lighter than memory foam. It’s also perforated, which creates channels for warm air to travel away from your body.
- Memory Foam Layer: Casper’s middle foam layer is composed of Zoned Support™ memory foam. The foam under your shoulders is softer, while the foam under your hips is firmer. These ergonomic zones help to keep your spine in its natural alignment, which can prevent or alleviate back pain.
- Durable Base: At the base of the mattress is a thick foam layer. It’s a bit firmer, so it keeps you from sinking too far into the mattress. It also prevents sagging.

Inside the Amerisleep Mattress
- Celliant Cover: Celliant material is engineered to transform your body heat into infrared energy that cools and rejuvenates your muscles, regardless of your body type. It’s a great pick if you notice that you are frequently sleeping hot.
- Bio-Pur Foam: Amerisleep’s proprietary Bio-Pur foam is eco-friendly and breathable. It has an open-cell structure that improves air circulation under your body.
- Affinity Transition Foam: This foam layer is designed with targeted ergonomic support that enhances spinal alignment and eases stress on pressure points.
- Support Layer: The polyurethane foam base is 7” thick. It serves as a durable, supportive foundation for the whole mattress.
Compare Our Scores
We put both the Casper and Amerisleep AS3 mattresses through a comprehensive lab evaluation that tests 14 important criteria. The chart below shows how each mattress scored across all of the categories.
Casper | Amerisleep | |
Shipping | 10 | 8 |
Trial Period | 9 | 9 |
Return Policy | 10 | 10 |
Warranty | 9 | 10 |
Set-Up Test | 8 | 9.5 |
Motion Transfer Test | 8 | 8.75 |
Edge Support Test | 9.5 | 8 |
Pressure Relief Test | 8.5 | 7.75 |
Spinal Alignment Test | 9.5 | 8.25 |
Responsiveness Test | 10 | 7 |
Cooling Evaluation | 7 | 8 |
Durability Evaluation | 8 | 8.5 |
Customer Service Score | 9 | 9 |
Social Impact Score | 9 | 4 |
TOTAL SCORE | 9.1/10 | 8.4/10 |
Sleeping Position
Mattress firmness can make a huge impact on comfort. Fortunately, Casper and Amerisleep both have a medium-firm feel that works for all sleep positions.
Still, side sleepers will be more comfortable on the Casper. It scored higher in pressure relief and spinal alignment. Back and stomach sleepers could fare well on either bed, although Casper’s superior spinal alignment is a big plus if you have back pain.
Combo sleepers should go with Casper, since it scored a perfect 10/10 on our responsiveness assessment. Amerisleep only scored 7/10, which isn’t bad, but doesn’t compete with Casper’s perfect score.
Sleep Trial Period and Warranty
You may pay more for the Amerisleep, but you are protected for longer. Amerisleep’s 20-year warranty is 2 times longer than Casper’s warranty. It also covers more nuanced defects. For example, Amerisleep will completely replace your mattress if it develops sagging deeper than 0.75”, while Casper covers 1” impressions.
Keep in mind that Amerisleep requires you to pay a prorated cost during the second 10 years of the warranty.
Both companies provide free shipping in the continental U.S. They also both offer 100-night sleep trials and full refunds during the trial period.
Is Casper or Amerisleep the Best Mattress?
You may already have a good idea of which mattress is the right fit for your needs. Whichever mattress you choose, we’re confident you’ll experience a comfy night’s sleep. Each of these mattress models receive rave reviews from customers and neither scored below average on any of our evaluation criteria. Plus, if your new mattress is just not the right fit, you can return it during the 100-day trial period.
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