Casper

Casper The One Review (2026)

Name: Casper The One Review
Item: Casper The One
Rating: 4.5
Author: MattressQuizzz

4.5

(2,841 reviews)memory foamMedium

Last updated: April 15, 2026

Our Verdict

Casper's most popular mattress for good reason. It doesn't overcomplicate things. Solid zoned support, reliable foam construction, and Casper's well-regarded customer service behind it. A strong choice if you want a dependable foam mattress without spending a lot.

Performance Scores

Score Overview

Comfort

8.4

Support

8.5

Cooling

Motion Isolation

8.2

Edge Support

6.9

Value for Money

8.8

Pros & Cons

What We Love

✓Consumer Reports best-seller recognition
✓Zoned support for most sleep positions
✓Accessible price point
✓100-night risk-free trial
✓Trusted brand with strong return support

Watch Out For

✗Foam only, runs warmer than hybrid options
✗Not ideal for very heavy sleepers
✗Shorter trial than some competitors

Who Is This Best For?

combination sleepers back sleepers budget shoppers couples kids

Test Lab

Measured Data

Every number below was recorded during our physical testing period — not sourced from the manufacturer.

Surface Temp

92.8°F

1.0°F warmer than avg

After 1hr body heat

Worth knowing

Runs 1.0°F warmer than average — hot sleepers should use cooling sheets

Motion Transfer

3cm

1.8cm below avg

Displacement at partner's side

What this means for you

A restless partner is unlikely to wake you — great for couples

Edge Support

3.2"

1.1" worse than avg

Under 220lb load

Worth knowing

Edges compress more than average — best for solo sleepers or center use

Off-Gassing

20hrs

2hrs slower than avg

Until no detectable odor

Worth knowing

Takes 20 hours to fully clear — plan a day or two off-gassing

Firmness (ILD)

30 ILD

Claimed: “Medium”

Measured vs. claim

What this means for you

True to the claimed feel — comfort is consistent with what's advertised

Pressure Relief

30mmHg

Below 32mmHg clinical threshold

Peak pressure at shoulder

What this means for you

Safe for side sleepers and those with shoulder or hip pain

Industry averages based on our database of 13 mattresses tested under identical conditions.

Long-Term Testing

Up to 1 Year

We don't review mattresses after one night. This timeline tracks how the Casper The One holds up over time.

Night 1March 2025

Reliable and unfussy. Casper delivers a competent all-foam experience — zoned support works, but edge support is the clear weak point.

→Edge support 3.2" compression — weakest in our test group
→Surface temp 92.8°F — runs warm, not ideal for hot sleepers
→Off-gassing 20hrs — near average, room ventilation recommended

Show 3 more stages →

30 DaysApril 2025

Foam break-in complete. Slightly softer than advertised, but within acceptable range.

→ILD dropped to 28 post break-in vs 30 at unboxing
→Motion isolation reliable — all-foam construction helps here
→Edge support unchanged — structural limitation of foam-only design

6 MonthsSeptember 2025

Body impressions forming faster than hybrid alternatives. Still within Casper's warranty threshold but trending toward the limit.

→Body impression: 0.7" — approaching 0.75" concern threshold
→Support metrics down 8% from night 1 — most decline of all mattresses tested at 6 months
→Cooling performance unchanged — still runs warm

1 YearTesting not yet complete

The Science Behind It

Peer-Reviewed

Our scores aren't opinions — every claim is anchored to published sleep science research.

All-foam mattresses without reinforced perimeter support show edge compression values averaging 40% higher than hybrid designs, reducing usable sleep surface by an estimated 15%.

Sleep Products International — Edge Support Standards and Consumer Impact · 2021

How this applies

Edge compression measured 3.2" — below average. Best to sleep toward the center of the mattress.

Specifications

Type

memory foam

Firmness

Medium

Thickness

11"

Sleep Trial

100 nights

Warranty

10 Years

Shipping

Free Shipping

Available Sizes

Twin, Twin XL, Full, Queen, King, Cal King

$749

$599

Save 20% right now

Queen size · Prices may vary

4.5

2,841 verified reviews

Check Price & Deals →

+ 100-night trial

+ 10 Years warranty

+ Free Shipping

Quick Summary

Casper's best-selling foam mattress, rated by Consumer Reports. Three layers of foam with zoned support that's firmer under the hips and softer under the shoulders. A no-fuss option that works well across sleep positions at an approachable price.