Casper One Mattress Review 2026: Worth Buying?

Shopping for a mattress feels harder than it should. You read ten reviews, and each one says something different. This review cuts through that noise.

The Casper One is the cheapest mattress in Casper’s lineup. It is an all foam bed, it ships in a box, and it sits at a medium firm feel that most sleepers can handle. Casper rebuilt its entire range in 2024, and the One replaced the classic Casper Original that made the brand famous.

So does the budget model still carry the Casper name well? I looked at lab data, tester feedback, owner complaints, and the raw specs. Some results impressed me. Others did not. The pressure relief scores, in particular, tell a story Casper’s marketing page skips.

In a Nutshell:

• The Casper One is a medium firm all foam mattress rated 6 out of 10. It uses three foam layers and stands 11 inches tall on Casper’s spec sheet, though one lab measured its sample at 10 inches. There are no coils, no gel, and no cooling bands.
• It fits sleepers under 230 pounds best. Side sleepers and back sleepers in that weight range get solid alignment and gentle cushioning. Heavier sleepers and stomach sleepers above 230 pounds tend to sink past the comfort layers.
• Motion isolation is a real strength. Testers barely felt a partner move across the bed. Couples with different schedules will appreciate this.
• Pressure relief is the weak spot. One lab scored it 6.0 out of 10, well below the 8.7 average, and blamed the thin 3 inch comfort layer. Pressure points can build under the lower back.
• Off gassing lasts longer than average. The smell arrives strong and can take up to 12 days to fade, compared to roughly 6 days for a typical foam bed.
• Pricing sits slightly under the foam mattress average. A queen lists near $995 and drops lower during Casper’s frequent sales. You also get a 100 night trial and a 10 year warranty.

What Is the Casper One Mattress?

Last update on 2026-10-18 / Affiliate links / Images from Amazon Product Advertising API

The Casper One is the entry level model in Casper’s current range. Casper launched it in 2024 when the brand retired the old Casper, Casper Original, and Casper Select beds. It is the only pure foam option left in the lineup.

Think of it as the simplified version of the mattress that started the bed in a box trend. You get three foam layers, a stretchy knit cover, and a single firmness option. There is no zoned support, no reinforced perimeter, and no special cooling technology.

Casper sells it in every standard size plus a split king. A queen weighs about 76 pounds, so plan on help carrying the box upstairs.

Who is it built for? Casper aims it at budget shoppers who want a recognized brand without paying hybrid prices. The company positions it as a balanced feel that works across sleeping positions.

The Casper Cloud One, added in 2025, is the softer cousin with foam columns instead of a solid core.

Unboxing the Casper One: What Actually Arrives

Your mattress shows up compressed, rolled, sealed in thick plastic, and stuffed into a tall cardboard box. Delivery usually lands one to two weeks after ordering. The driver leaves it at your door, so clear a path first.

The box for a queen is heavy and awkward rather than impossibly heavy. Two people make this easy. One person can drag it if the floor is smooth.

Cutting the plastic is the fun part. The mattress hisses, swells, and unrolls across the frame within a minute or two. Most of the shape returns in under an hour. Casper suggests giving it a full day before you judge the feel.

The cover is thin and soft with a light stretch. There is no tufting and no quilted top, which keeps the look plain and modern. No handles are sewn into the sides, and you will notice that during setup.

One warning. The smell hits immediately and it is strong. Open a window.

Inside the Casper One: Layers and Materials

Last update on 2026-10-18 / Affiliate links / Images from Amazon Product Advertising API

The build is simple, and simplicity is the whole point here. Three foam layers sit inside a polyester knit cover.

The top layer is 1.5 inches of open cell poly foam. It is bouncy, breathable, and springs back fast. Below that sits 1.5 inches of memory foam that softens impact around your joints.

The bottom 7 inches is high density support foam. This is the Casper Core, and it carries the load without coils.

That gives you a 3 inch comfort layer, which is thinner than the 4.1 inch average across tested foam mattresses. The number matters, and you will see why in the pressure relief section.

Casper removed fiberglass from the fire barrier in early 2024 and switched to a rayon based material. That change is worth knowing if you have read horror stories about fiberglass leaking from cheap foam beds.

Everything is CertiPUR US certified and assembled in the United States.

How Firm Is the Casper One?

Casper rates the One as medium firm, and independent testing agrees at 6 out of 10. That places it right in the middle of the scale, slightly to the firm side.

Here is what that feels like in practice. You rest on the mattress rather than in it. Sinkage measured just 1.77 inches in lab testing, compared to a 2.15 inch average. Body contour is slight.

Some people love that floating feel. Others miss the deep hug of classic memory foam.

Fast response is part of the experience too. The foam rebounds to shape in roughly 0.4 seconds, which is quicker than most foam beds. Rolling over is easy, and you never feel stuck.

Firmness perception shifts with body weight. Lighter sleepers under 130 pounds will read this as firmer. Sleepers above 230 pounds will read it as softer, because they push deeper into the support core.

There is only one firmness option, so there is no way to adjust.

Top 3 Alternative for Casper One Mattress

Last update on 2026-10-17 / Affiliate links / Images from Amazon Product Advertising API

Leesa Original 10 Inch Foam Mattress

Last update on 2026-10-18 / Affiliate links / Images from Amazon Product Advertising API

GhostBed Classic 11 Inch Memory Foam Mattress

Last update on 2026-10-19 / Affiliate links / Images from Amazon Product Advertising API

Zinus Green Tea Memory Foam Mattress

Pressure Relief and Support: The Honest Result

This is where opinions split, so I will give you both sides.

Lab testing scored the Casper One at 6.0 out of 10 for pressure relief, far under the 8.7 average. The tester felt pressure points building in the lower back after only a few minutes in one position. The thin comfort layer lets your body reach the hard support foam too quickly.

Sleep Foundation testers reached a friendlier conclusion and gave it 8 out of 10. Their side sleepers liked the cushioning at the hips and shoulders without the sinking feeling.

Both results can be true. The bed cushions lighter bodies fine and struggles under heavier ones.

Support for spinal alignment is genuinely good. The firm core keeps hips level with shoulders for most sleepers under 230 pounds.

My read: if you weigh under 180 pounds and sleep on your back or side, you will likely be comfortable. If you have shoulder or hip pain, look at a thicker mattress.

Motion Isolation for Couples

Good news for anyone sharing a bed with a restless partner. The Casper One handles motion well.

Testers rated motion isolation 8 out of 10 and said movement on the far side barely registered. The all foam build absorbs energy instead of passing it along the surface.

Lab data adds nuance. The acceleration reading was 9.42 m/s, about 7 percent more motion than average. The minimal sinkage is the reason. Foam that compresses deeply absorbs energy better, and this bed does not compress deeply.

The saving grace is duration. Motion drops to near zero within 0.72 seconds, so any disturbance is brief rather than lingering.

In real terms, a partner climbing into bed will cause a small bump that fades fast. A partner tossing all night will not ripple across to your side.

There are no coils, so the mattress is completely silent. No squeaks, ever.

Cooling and Temperature Control

The Casper One is an average performer here, and I want to set expectations clearly.

It scored 8.0 out of 10 for cooling in lab tests, slightly below the 8.7 average. Surface temperature peaked at 89.6 F after 15 minutes of body contact.

The mattress has no cooling features at all. No gel infusion, no copper, no phase change material, no convoluted foam, and no coils for airflow. What helps is the open cell top foam and the shallow sinkage, since less of your body is buried in foam.

Sleep Foundation testers described it as neither hot nor cold. One tester said he never overheated but never felt cool either.

Translation: average sleepers will be fine. Hot sleepers will not be. If you wake up sweating on your current bed, this is not the fix, and a cooling hybrid makes more sense.

Edge Support, Bounce and Ease of Movement

Edge support gave mixed results, and the split is interesting.

Sitting on the edge is surprisingly good. Compression measured 3.5 inches, better than the 4.04 inch average, and the perimeter held its shape. Putting on shoes in the morning feels stable.

Lying near the edge is weaker. There is no reinforced perimeter foam, so the sides compress more than the middle. Sleepers above 230 pounds may feel a slight roll off sensation. Couples who use the full width of the bed will notice this.

Bounce measured 8.77 inches of total rebound, a moderate result. Combined with the fast recovery time, the bed is easy to move around on.

Sex performance scored 8.3 out of 10. The surface is quiet and responsive enough, though the lack of coils means less lively pushback than a hybrid delivers.

Overall these are respectable numbers with no dramatic failures.

Off Gassing and the First Two Weeks

Here is the complaint I take most seriously.

New foam smell is normal. Every bed in a box has it. The Casper One simply has more of it and keeps it longer.

Testing scored off gassing at 6.7 out of 10. The initial odor was strong, and it took 12 full days to fade completely. The average across foam mattresses is roughly 6 days.

Twice the average is a real inconvenience. Owner reviews echo this, and some sleepers with chemical sensitivities found the first week rough.

What helps? Unbox the mattress in a spare room if you can. Open windows and run a fan across the surface. Leave the bed bare for the first 24 to 48 hours instead of dressing it immediately.

The smell is not dangerous. The foams carry CertiPUR US certification, which limits certain chemicals. Still, plan your delivery so you are not sleeping on it the same night.

Sizes and Prices in 2026

The Casper One sits slightly under the average foam mattress price, roughly 10 percent below.

List prices run near $695 for twin and twin XL, $895 for full, $995 for queen, and $1,395 for king and California king. A split king option is also available.

Casper runs sales constantly. Real street prices often fall into the $599 to $1,358 range across sizes, and holiday events push them lower. Very few people pay full list.

Height is listed at 11 inches, though one lab measured its review sample at 10 inches. That gap is worth noting if exact sheet depth matters to you.

A queen weighs about 76 pounds. A king reaches 94 pounds.

Is it good value? That depends on your standard. It is cheaper than a hybrid and cheaper than Casper’s other models. Against budget rivals like Siena or Zinus, though, the price gap is harder to justify on performance alone.

Trial, Warranty and Delivery Terms

Casper’s policies are solid without being generous.

You get a 100 night sleep trial. That is shorter than the 164 night average across brands, and much shorter than Nectar’s year long trial. Still, 100 nights is plenty of time to decide.

There is a 30 night adjustment period built in. You must keep the mattress for at least 30 nights before requesting a return. Foam needs time to break in, so this rule is reasonable.

Returns and shipping are both free in the 48 contiguous states. Alaska and Hawaii cost extra. Casper picks up the mattress and refunds you in full.

The warranty runs 10 years and covers manufacturing defects. Normal wear and accidental damage are excluded, which is standard across the industry.

White glove delivery with setup and old mattress removal is available for an extra fee in many areas. For a 76 pound queen, that upgrade is worth pricing out.

What the Casper One Does Not Do Well

Authentic reviews name the flaws, so here they are without softening.

Pressure relief underdelivers. The 3 inch comfort layer is thin for a mattress approaching $1,000. Testers felt pressure building in the lower back within minutes.

It fails heavier sleepers. Anyone above 250 pounds should skip it entirely. Between 230 and 250 pounds, results are unpredictable.

Off gassing lasts about 12 days. That is double the normal wait.

Cooling is basic. No gel, no coils, no cooling fabric. Hot sleepers should look elsewhere.

Edge support while lying down is weak. No perimeter reinforcement means the sides give way.

Durability is modest. With no coil layer, expect roughly seven years of useful life rather than a decade.

One lab ranked it in the bottom 15 percent of all mattresses it has tested. That is a harsh verdict, and it comes from measured data rather than opinion. The Casper One is competent, not excellent.

Pros and Cons of the Casper One

Pros

• Very fast foam response at 0.4 seconds, so moving around never feels like a struggle
• Strong sitting edge support at 3.5 inches of compression, better than most foam beds
• Good motion isolation that keeps a partner’s movement from waking you
• Balanced medium firm feel that suits back and side sleepers under 230 pounds
• The lowest price in Casper’s current lineup, with frequent discounts available
• Fiberglass free fire barrier and CertiPUR US certified foams
• Free shipping, free returns, and a 100 night trial with no hidden fees
• Completely silent, since there are no coils or springs inside

Cons

• Pressure relief scored just 6.0 out of 10, well below average for the price
• Off gassing smell is strong and can take up to 12 days to clear
• No cooling features at all, so hot sleepers will feel warmth build up
• Thin 3 inch comfort layer and 10 to 11 inch height limit support for heavier bodies
• Lying edge support is weak with no reinforced perimeter
• Only one firmness option, so there is no way to adjust the feel
• The 100 night trial is shorter than many competitors offer
• Cheaper rivals match or beat its performance in several test categories

Who Should Buy the Casper One in 2026?

Let me make this simple.

Buy it if you weigh under 200 pounds, sleep on your back or side, and want a recognized brand at a moderate price. Buy it if you share a bed and need motion isolation. Buy it if you dislike the sinking feeling of traditional memory foam and prefer a floating, responsive surface.

Skip it if you weigh over 230 pounds, sleep on your stomach, run hot at night, or have chronic hip and shoulder pain. The thin comfort layer simply will not give you enough cushioning.

Also skip it if odor sensitivity is a concern, because 12 days is a long wait.

My honest verdict is that the Casper One is an acceptable mattress at a fair price. It is not a standout. The brand name carries real weight, and the trial protects you, but the test data shows several budget rivals performing better for less money. Try it during a sale, and use the full 100 nights.

Frequently Asked Questions

How firm is the Casper One mattress?

The Casper One is medium firm and rates 6 out of 10 on the standard firmness scale. Most sleepers describe it as balanced rather than plush or hard. There is only one firmness option available.

Is the Casper One good for side sleepers?

Yes, for side sleepers under 230 pounds. The foam cushions hips and shoulders while keeping the spine aligned. Heavier side sleepers often sink too far and lose support.

How long does Casper One off gassing last?

The smell is strong at unboxing and typically clears within 12 days. Ventilate the room and leave the mattress uncovered for the first day or two to speed this up.

Does the Casper One sleep hot?

It sleeps about average. There are no cooling features inside, but the open cell top foam and shallow sinkage prevent heat from trapping badly. Hot sleepers should consider a hybrid instead.

How long does a Casper One mattress last?

Expect around seven years of comfortable use. The all foam build with no coil layer limits long term durability compared with hybrid mattresses. The warranty covers defects for 10 years.

Can I return the Casper One if I dislike it?

Yes. Casper offers a 100 night trial with a 30 night minimum break in period. Returns and pickup are free in the contiguous United States, and you receive a full refund.

Is the Casper One fiberglass free?

Yes. Casper switched to a rayon based fire barrier in early 2024, so current Casper One mattresses contain no fiberglass.