Amerisleep AS4 vs Casper The One
Detailed side-by-side comparison — pricing, specs, performance ratings, and our pick.
| Feature | Amerisleep AS4 | Casper The One |
|---|---|---|
| Overview | ||
Type | foam | Memory Foam |
Firmness 1 = softest, 10 = firmest | 3.5 / 10 | 6.5 / 10 |
Queen Price Current / sale price | $1,149 | $799 |
Trial Period Return window | 100 nights | 100 nights |
Warranty | 20 years | 10 years |
| Performance Ratings | ||
Cooling Hot sleepers | Average | Moderate |
Motion Isolation Partners, light sleepers | Excellent | Excellent |
Pressure Relief Hip/shoulder pain | Excellent | Good |
Edge Support Sit/sleep near edge | Average | Fair |
Durability Long-term performance | Good | Good |
| Compatibility & Features | ||
Adjustable Base Head/foot elevation | ✓ Yes | ✓ Yes |
Split King Support Two Twin XL per couple | ✓ Yes | ✓ Yes |
Dual Comfort Zones Different firmness per side | — | — |
Smart Features App, sensors, auto-adjust | — | — |
Financing | Available | Affirm |
| Materials & Safety | ||
Certifications Organic / non-toxic | None listed | CertiPUR-US |
Off-Gassing New-foam smell concern | — | CertiPUR-US certified foam |
| Best For | ||
Ideal sleeper profiles |
|
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| Actions | ||
Need Help Deciding?
For most sleepers, we recommend the Amerisleep AS4 over the Casper The One. It scores higher in pressure relief, edge support and delivers stronger overall value. The Casper The One is the better choice only if budget is paramount — it saves roughly $350.
Amerisleep AS4 vs Casper The One: What Actually Differs
The Amerisleep AS4 is a foam build, while the Casper The One is a memory foam — that single difference drives most of the cooling, motion, and feel decisions below. The Amerisleep AS4 stands 12" tall versus 11" for the Casper The One — a 1.0" gap that matters if you need deep-pocket sheets or are pairing with an adjustable base. The Casper The One is the firmer of the two at 6.5/10 (medium-firm), and the Amerisleep AS4 sits at 3.5/10 (medium-soft) — a meaningful enough gap that sleeper position and weight should drive the choice. The single largest performance gap is in pressure relief: the Amerisleep AS4 rates noticeably higher than the Casper The One, which is the deciding factor if that dimension is high on your list. On a Queen, the Casper The One runs $799 versus $1,149 for the Amerisleep AS4 — roughly $350 (30%) less, which is enough to factor into the decision unless the pricier model wins clearly on the specs you care about.
Which Is Better For Your Sleep Style?
Higher pressure-relief rating, which is what protects hip and shoulder contact points in the side position.
Firmness of 6.5/10 is closer to the medium-firm sweet spot back sleepers need for lumbar support (vs 3.5/10).
Firmer at 6.5/10 vs 3.5/10 — stomach sleepers need the extra support to keep the pelvis from sinking and arching the lower back.
Cooling rated the same on both — neither has a heat-management edge in our spec data.
Durability and edge-support ratings are equivalent — either holds up.
Softer at 3.5/10 vs 6.5/10 — lighter sleepers compress less, so they typically need the softer of two options to get proper contouring.
Motion isolation rated the same on both — neither has a transfer-disturbance edge.
Price Comparison (Queen)
| Mattress | MSRP | Current | Sale? |
|---|---|---|---|
| Casper The One | $999 | $799 | Save $200 |
| Amerisleep AS4 | $1,649 | $1,149 | Save $500 |
The Casper The One is the budget choice at $799 — $350 less than the Amerisleep AS4 ($1,149). That's a 30% gap, which is worth weighing against the spec differences before deciding which delivers better value for your situation. Both are currently below MSRP.
Amerisleep AS4
Strengths
- ✓Medium-soft feel excellent for side sleepers who need shoulder and hip relief
- ✓HIVE® hex cutouts in the base layer provide zoned support
- ✓Plant-based Bio-Pur foam more breathable than traditional memory foam
Considerations
- —Too soft for stomach sleepers — spinal alignment risk
- —All-foam — less breathable than AS4 hybrid (when available)
Casper The One
Strengths
- ✓Three-layer foam build with Casper Core support
- ✓Strong motion isolation for an all-foam bed
- ✓Split King is sold from the PDP
Considerations
- —No coil edge feel
- —No active Snow cooling package
- —Medium-firm feel is less plush than Cloud One
Who Should Buy Which?
Choose the Amerisleep AS4 if you…
- →Side sleepers / pressure relief
- →Sitting near the edge
- →Softer feel seekers
Choose the Casper The One if you…
- →Budget-conscious shoppers
- →Organic / non-toxic priority shoppers
- →Firmer support seekers