Amerisleep Vs Casper Mattress Comparison

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Trying to choose between the Amerisleep and the Casper? You’ve got good taste! The original Casper mattress helped pioneer beds-in-a-box, and it remains one of the most popular online mattresses. Meanwhile, the Amerisleep line of mattresses offers five distinct mattress options for all kinds of sleepers.

In this mattress comparison, we’ve pitted the original Casper against the Amerisleep’s most popular mattress model, the Amerisleep AS3. Let’s see how these two powerhouses stack up!

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Amerisleep Vs Casper Mattress Overview

The Casper and the Amerisleep AS3 are both popular online mattresses, but they’re best suited to different types of sleepers. Here’s a quick overview of who might prefer the Amerisleep and who might like the Casper.

Who Should Get The Amerisleep?

  • Side sleepers, who need plenty of pressure relief
  • Folks who want to choose from several firmness options (While we’re talking about the AS3 here, the Amerisleep line does offer four other models to choose from)
  • People who prefer a mattress with a more slow-moving feel

Learn more about all of the Amerisleep models in our comprehensive Amerisleep mattress review.

Who Should Get The Casper?

  • People who are looking to save some money
  • Folks who want a bouncier mattress
  • Back sleepers who prefer extra lumbar support

Curious about the Casper? Check out our in-depth Casper mattress review.

Amerisleep Vs Casper Mattress Video Comparison

Want to dive deep into the Amerisleep AS3 and the original Casper? Then check out our in-depth video review! Our reviewer, Marten, will assess each mattress’s construction and share his experience with sleeping in all positions on these beds.


Similarities Between The Amerisleep And Casper?

The Amerisleep AS3 and the Casper are sold by different brands and feature different constructions. Still, they do have a few factors in common.

RELATED: Best Memory Foam Mattress

Amerisleep Mattress Review

Key Differences Between The Amerisleep And Casper?

These mattresses have many more differences than they do similarities. Here’s a quick overview.

  • The Amerisleep AS3 is thicker than the Casper
  • The mattresses feature different materials in their comfort layers: The AS3 features contouring Bio-Pur foam, while the Casper uses a responsive polyfoam
  • These mattresses have different feels (More on that below)
  • The Casper costs less than the Amerisleep AS3
  • The Casper is a bit firmer than the Amerisleep AS3
  • The Amerisleep line offers five options to choose from

Casper Original Mattress Review

Firmness And Feel Differences (Including Firmness Rating)

When you’re shopping for a new mattress, it’s critical to consider firmness and feel. These factors will have a major impact on whether a mattress is appropriate for your preferred sleep position(s) and other sleep needs. So let’s take a look at the firmness and feel on both the Casper and the Amerisleep AS3!

How Firm Are The Casper And Purple Mattresses?

We ranked the Amerisleep AS3 around a 6.5/10 on the firmness scale, and we ranked the original Casper around a 7/10. (Again, note that this Amerisleep line also offers four other models with different firmness options.) The industry standard for medium firmness is 6.5/10, so this suggests the Amerisleep AS3 is right around medium-firm while the Casper is a touch firmer.

That said, note that firmness is a bit subjective. Depending on a person’s body weight, they might rank these mattresses slightly firmer or softer. For instance, lighter people might find these to be two of the best soft mattresses.

Sleeping On The Amerisleep And Casper Mattresses

We hopped onto the Amerisleep and Casper mattresses and tried them out in a number of sleeping positions. Keep reading to see how supportive and comfortable these mattresses really are.

Amerisleep AS3

We felt great while back sleeping on the Amerisleep AS3. The mattress offered a good balance of comfort and support, so we enjoyed some pressure relief while our spine remained properly aligned.

Amerisleep AS3 - Back Sleeping

While side sleeping on the Amerisleep AS3, we enjoyed decent pressure relief around the shoulder and hip. Larger folks or people with sensitive joints might find that they need even more pressure relief, in which case they might want to consider the softer Amerisleep AS4 or AS5.

We found the Amerisleep AS3 to be too soft for stomach sleeping. Our hips bowed into the mattress a bit and pulled the spine out of alignment. Strict stomach sleepers might want to look at the firmer Amerisleep AS1.


As with the Amerisleep AS3, we felt great while back sleeping on the Casper. Our hips sank in for just a touch of pressure relief, but not so much that our spine was misaligned. We enjoyed plenty of spinal support and especially great lumbar support.

We experienced some pressure while side sleeping on the Casper. Lighter folks might enjoy better pressure relief, but average- and heavy-weight side sleepers will probably want to look for a plusher mattress.

Casper Mattress - Side Sleeping

The Casper offered us decent support while stomach sleeping, and we felt the support layer holding up our hips. That said, strict stomach sleepers will probably want to look for a firmer mattress overall.

What Do The Amerisleep And Casper Mattresses Feel Like?

The Amerisleep AS3 has a bit of memory foam feel and a fairly slow response to pressure. That said, the Bio-Pur foam is more responsive than conventional memory foams, so sleepers shouldn’t feel stuck in this mattress. It’s not as bouncy as latex, but it’s still pretty easy to move around.

The Casper has a very bouncy and responsive foam feel. It’s easy to move around on top of this mattress. It features a Zoned Support system that is firmer near the middle of the mattress (to support the spine and hips) and softer near the head and foot (for pressure relief).

Average Weight Sleepers – 130 lbs – 230 lbs

The original Casper mattress should offer a pleasant balance of comfort and support to average-weight back sleepers, and it offers better lumbar support than the Amerisleep AS3 thanks to its Zoned Support system. This mattress could suit some side sleepers, but folks who prefer a softer feel or weigh closer to 230 pounds will prefer the softer Amerisleep AS3 or another mattress for side sleeping. The Casper offers more support to average-weight stomach sleepers than the Amerisleep AS3.

Like the Casper, the Amerisleep AS3 should offer a nice balance of support and comfort to average-weight back sleepers. Side sleepers who weigh closer to 230 pounds will probably prefer the Amerisleep AS3’s softer feel over the Casper. The Amerisleep AS3 is probably not supportive enough for average-weight stomach sleepers.

Heavyweight Sleepers – Over 230 lbs

Heavyweight back sleepers should find a decent balance of support and comfort on the Casper, although folks who weigh 300 pounds or more will probably want to look for a more supportive mattress overall. The Casper might not offer enough pressure relief to heavyweight side sleepers, who could press through the comfort layers into the firmer support layer underneath. The Casper might offer enough support to stomach sleepers who weigh closer to 230 pounds, but heavier folks will probably want a firmer mattress.

The Amerisleep AS3 might not offer enough spinal support to heavyweight back sleepers. It will offer more pressure relief than the Casper to heavyweight side sleepers, but folks in this category will probably prefer one of the softer Amerisleep models (such as the AS4 or AS5). The Amerisleep AS3 is probably not supportive enough for heavyweight stomach sleepers.

Lightweight Sleepers – Under 130 lbs

The Casper offers a pleasant balance of support and comfort to lightweight back sleepers, including additional lumbar support. It should be pressure-relieving enough for most lightweight side sleepers. It’s supportive enough to help lightweight stomach sleepers maintain proper spinal alignment through the night.

Like the Casper, the Amerisleep AS3 offers a great balance of comfort and support for lightweight back sleepers. It should also provide comfortable pressure relief for lightweight side sleepers. This mattress might be supportive enough for lightweight stomach sleepers, but the Casper is probably a better choice for this sleep position.

Mattress Construction Differences

Now that you know what it feels like to lie on top of the Amerisleep AS3 and the Casper, let’s take a look at what’s inside of these mattresses! We’ll compare their constructions layer by layer.


The Amerisleep AS3 features a soft and breathable cover that helps promote airflow.

The Casper’s cover is soft, very breathable, and made from recycled bottles.

Comfort Layers

The Amerisleep’s top comfort layer is made from 3” of Bio-Pur foam, an open-celled foam that’s more breathable than conventional memory foam. It’s also bouncier than standard memory foam, so you shouldn’t feel stuck in this mattress. Different models in the Amerisleep line have different amounts of this Bio-Pur foam; the AS1 has the least while the AS5 has the most. Beneath the Bio-Pur foam layer, there’s a HIVE Transition layer with a zoned construction, which creates subtle differences in firmness across the mattress. You’ll find this layer in the AS2 models and up.

Amerisleep AS3 - construction and foam layers

The Casper’s top comfort layer is made from the brand’s proprietary AirScape foam, which is perforated to allow for more breathability and airflow. This layer is simultaneously plush and responsive. Beneath it, there’s a Zoned Support layer made of memory foam. Instead of being one solid piece, this layer is firmer near the center of the mattress (for extra support) and softer near the head and foot (for pressure relief).

Casper Mattress - Construction And Foam Layers

Support Layer

The Amerisleep AS3’s support layer is made from a Bio-Core base foam that is high-density and supportive.

The Casper’s support layer is made from high-density polyfoam, which provides overall support to the mattress.

Mattress Height

The Amerisleep AS3 is 12” thick, while the Casper is a touch shorter at 11” thick.

Amerisleep And Casper Mattress Size Options And Price

To see the most up-to-date size and pricing information for the Amerisleep AS3 and Casper mattresses, check out the charts below.

Amerisleep AS3

Size Dimensions Price
Twin 38″ x 74″ x 12″ $1149
Twin XL 38″ x 80″ x 12″ $1199
Full 54″ x 75″ x 12″ $1349
Queen 60″ x 80″ x 12″ $1499
King 76″ x 80″ x 12″ $1899
California King 72″ x 84″ x 12″ $1899
Split King 38″ x 80″ x 12″ (x2) $2398


Size Dimensions Price
Twin 38″ x 75″ x 11″ $595
Twin XL 38″ x 80″ x 11″ $695
Full 53″ x 75″ x 11″ $995
Queen 60″ x 80″ x 11″ $1095
King 76″ x 80″ x 11″ $1295
California King 72″ x 84″ x 11″ $1295

Amerisleep And Casper Performance Differences

Alright, by now you have a pretty clear sense of these mattresses’ constructions plus what it feels like to sleep on top of the Amerisleep AS3 and the Casper. Let’s round out this comparison with an assessment of some additional key performance metrics. We put these mattresses through a range of tests to assess their temperature regulation, motion isolation, edge support, and more. Also, make sure to check out our other popular Amerisleep and Casper comparisons such as Amerisleep vs Leesa and Casper vs Tempur-Pedic.

Sleeping Hot Or Cold

Both the Amerisleep AS3 and the Casper are all-foam mattresses, which can be known for trapping heat. That said, each mattress uses materials that help promote some cooling: The Amerisleep AS3 features a breathable cover and open-celled foam in its comfort layer, while the Casper features a breathable cover and perforated AirScape foam. We’re calling this a tie.

Motion Transfer

The Amerisleep AS3 is the winner here. Its thicker comfort layer does a better job of absorbing motion and minimizing motion transfer across the surface of the mattress. This could make it the better mattress for couples.

Edge Support

We called this a tie. Both the Amerisleep AS3 and the Casper offer decent edge support.

Casper Mattress - Edge Support


This was a close one, but the Amerisleep AS3 ekes out a win. Its materials are just a touch more durable. You’ll see this reflected in the bed’s longer warranty.


We observed some off-gassing from both the Amerisleep AS3 and the Casper. This should dissipate within a couple days.


Another tie! We didn’t observe any notable noise from either mattress.


People who are in the market for a mattress for sex are typically looking for a bed that makes it easy to change positions. The Casper is the winner of this category because it’s firmer, bouncier, and generally more responsive.

Warranty Info

The Amerisleep AS3 comes with a 100-night sleep trial and a 20-year warranty, while the Casper comes with a 100-night sleep trial and a 10-year warranty.

Gravatar for Marten Carlson

Marten Carlson

Marten is Senior Editor at Mattress Clarity. He covers the mattress industry as well as sleep science news. He is specifically interested in the connection between sleep and overall health. Marten has written for media publications like Consequence of Sound and received a master’s degree in Film Studies from Emory University. He comes from Franklin, Indiana, and spends all the time he can writing, directing, and acting in films. He has directed genre short films and features. His newest film, Starlets, recently premiered at the River Town Film Festival in Clinton, NJ. He also stars in the upcoming thriller, Sour Bear. His next film, At The Hop, is a hot rod actioner with a horror twist.