Buying a mattress online may be the popular way to buy a mattress in 2026, but there are still important details that you should confirm before you add to cart. At minimum, check the trial length (Endy offers a 365 night trial), the firmness level on a 1–10 scale, whether the foam is CertiPUR-US certified, and how returns and an old mattress’s pickup are handled. These tips for buying a mattress online will help you shop with confidence and find the best mattress for your body, even without trying it in-store. Below, we’ll go checkpoint by checkpoint, using the Endy Mattress and Endy Hybrid Mattress as real examples of a mattress built with online buyers in mind.
What Should You Check Before You Buy a Mattress Online?
Sleep Trial Length
A sleep trial lets you test a new mattress through weeks of real sleeping, not ten minutes on a showroom floor, before you commit to keeping it.Most online mattress purchases come with a trial of 100 to 365 nights, and the industry average lands closer to 90–120 nights. Many companies ask for a break-in period of about 30 nights before a return can start, since a new mattress needs time to soften and your body needs time to adjust to a new sleeping surface.Endy’s policy is more straightforward: mattresses purchased on or after November 15, 2025 come with a 365-Night Trial with no required break-in window, so you can request right away if you feel the mattress isn’t right for you. The trial policy allows one exchange for a different size, firmness, or type within the trial period, so a wrong first pick can be easily fixed.When shopping online, always check whether a restocking fee or return shipping cost comes out of your money back, since return policies vary between companies (Endy picks up your mattress, free of charge).
Match the Firmness Level to Your Sleeping Position
Mattress firmness is rated on a scale from 1 to 10, and a medium firm mattress usually scores around a 6 — the middle ground most people land on, and a combination that tends to suit couples with different sleeping styles.Your ideal firmness level depends on your sleeping position and body weight:
Side sleepers, especially those under 130 pounds, tend to prefer a soft mattress that eases pressure points around the shoulders and hips.
Back sleepers generally do well on medium to medium-firm support.
Stomach sleepers need a firmer mattress to keep the spine flat and stop the torso from sinking.
Sleepers over 230 pounds typically need firmer support to maintain proper alignment and prevent sagging.
Endy sells three firmness options — Plush, Medium-Firm, and Firm — instead of one fixed shape, so any person can match the mattress to their sleep style and weight rather than guessing.
Independently Certified Foam
Certifications such as CertiPUR-US® confirm a mattress’s materials were tested by someone other than the company selling it.CertiPUR-US certification means the foam is free of banned flame retardants, heavy metals, and formaldehyde, and meets standards for low emissions — GREENGUARD Gold is a similar certification often mentioned alongside it. Every Endy mattress uses CertiPUR-US certified foam and other materials tested by independent, accredited labs for content, emissions, and durability.Sustainable manufacturing matters to more shoppers now, so be careful of vague “organic” or “chemical-free” marketing that isn’t backed by real testing. The FTC’s Green Guides exist to keep those claims honest and protect buyers from empty promises.
Reputation and Customer Service
Before you buy, check that a real customer service team is reachable by phone or chat, not just a form that disappears into a queue.A company willing to answer customer questions before the sale is a decent preview of how it will serve you after. Good reviews tend to mention long-term durability and service, not just the unboxing moment, so read a few before you commit your money.Endy is committed to making great sleep accessible. It has over 30,000 5-star reviews to back up product claims, and customer service can easily be reached on a number of channels.
Ease of Unboxing
A bed-in-a-box mattress ships compressed and rolled, and it typically expands within a few hours of unboxing, though full expansion can take closer to a week.A new foam mattress may produce a mild odour at first as it releases volatile organic compounds, known as off-gassing. Airing out the bedroom for a day or two usually resolves it for CertiPUR-US certified foams, as the EPA notes when explaining why new products can have this smell.Check for reviews that mention whether the mattress can be set up alone or if it requires multiple people. If you live alone or have a disability, this is especially important.
Verify Dimensions
Measuring your room ensures mattress size compatibility before the box shows up — an average queen mattress measures roughly 202 cm x 152.5 cm, and a king takes up meaningfully more floor space for two people sharing a bed.Beyond the mattress itself, check that your frame can accommodate the full bed with proper, supportive contact and no gaps larger than a few inches, since an unsupportive frame affects both comfort and warranty coverage.
Mattress sizeMattress DimensionsMinimum Recommended room sizeCalifornia King72” x 84”Large bedroom (12’ x 12)King76” x 80”Large bedroom (10’ x 12)Queen60” x 80”Mid-size bedroom (10’ x 10)Full54” x 75”Mid-size bedroom (9.6’ x 10.6’)Twin XL39” x 80”Small bedroom (7’ x 10’)Twin39” x 75”Small bedroom (7’ x 10’)
You can read our full breakdown on mattress sizes in this guide.
Understand the Different Types of Mattresses
Different types of mattresses have different levels of firmness, support and longevity. Since they vary so much, it’s important to understand what they are to make the best purchasing decision for you. The main form of mattresses are:
Innerspring: core of steel coils
Memory foam: multiple layers of foam for exceptional motion isolation
Hybrid: combines coils with a soft foam top layer for support and airflow in one bed
Latex: naturally hypoallergenic and resistant to dust mites, and a
Other types of mattresses split the difference in various ways, but most sleepers land on memory foam or hybrid for an online purchase.The Endy Mattress is an all-foam build, with a cooling comfort layer, a transition layer to isolate motion, and a high-density support core that resists sagging over time.The Endy Hybrid adds 7-inch wrapped coils, enhanced edge support, and a quilted mattress cover lined with Endy Cooling Comfort Foam to keep you cool — one of the clearest benefits of a hybrid mattress at any price point.Each is also backed by Endy’s 15-year warranty to make sure that your purchase goes the distance.
Frequently Asked Questions
Is it safe to buy a mattress online without trying it first? Yes, as long as the retailer offers a generous sleep trial and a clear return policy — that safety net is more valuable than a few minutes spent sleeping on a showroom floor.How long does a mattress take to expand after unboxing? Most mattresses expand within a few hours, though full settling can take close to a week of regular sleeping.Do I need to know my firmness preference before ordering online? It helps—to help you get it right the first time, you can follow general guidance based on your preferred sleep position and body weight. However, brands offering multiple firmness options, like Endy’s Plush, Medium-Firm, and Firm range, lower the risk of guessing wrong for the first mattress you buy sight unseen.
Mattresses
