Our sleep experts have been testing mattresses, bedding and sleep technology for years, dedicating thousands of hours to honing our craft of honestly and thoroughly reviewing beds and sleep-related products. We’ve tested well over 300 beds from dozens of brands like Casper, Helix, Nectar, Purple, Leesa and many more. 

Our bed testers have varying body weights and types, heights, genders and sleep preferences, allowing us to provide an overarching assessment of each mattress from multiple viewpoints. We take pride in our mattress testing methodology, which includes analyzing characteristics such as firmness, feel, temperature regulation, motion isolation, edge support and special features.

Firmness

One of the primary characteristics we look for when selecting the best mattresses for side sleepers is firmness, which implies the amount of pressure relief the bed offers. During our testing process, our experts of varying weights and body types take turns lying on the bed in each sleeping position to determine how well they’ll cradle our primary pressure points — mainly shoulders, hips and knees. When lying on your side, the mattress must offer some «give» around these areas. If a mattress is too firm, it can push back on these pressure points too much and cause soreness, pain and even numbness. 

As I mentioned, firmness is subjective and varies from person to person — the driving force behind the creation of our Mattress Smasher 9000. With the mattress placed on the platform, we activate the device, which presses its arm into the middle of the bed. Our corresponding software then provides the objective firmness level on a scale of 1 to 10, with being the softest and 10 the firmest. 

We never recommend a mattress with a high firmness score for side sleepers. The sweet spot for side sleepers is typically around medium-soft, give or take some, depending on your weight, body type and personal preferences.

Feel

The feel of a mattress is another important element we analyze and review. Influenced by the types of foams and coils used in its construction, the feel of a bed is exactly how it sounds — what does it feel like when you lie on it? Is it bouncy and responsive? Is it easy to switch positions? Or does the dense memory foam conform around your body and hold your shape for a while? Does the mattress have a soft, plush pillow top feel, or is it more neutral? Are the coils or zoned support noticeable? We do our best to describe precisely what it feels like to lie on each bed to help you determine if it’s right for you without having to test them all yourself.

In determining the best feel for side sleepers, we look for beds with a softer and more plush sensation that cradles your curves and offers plenty of pressure relief for your hips and shoulders. 

Read more: Why The Foam in Your Mattress Matters

Temperature regulation

Each individual’s preferences, body type and even health conditions can influence how hot or cold a mattress feels. We’ve also found that mattress brands exaggerate the cooling capabilities of their beds. This is why we detail how hot or cool the mattress sleeps during our testing process so that you have a more accurate understanding of how it feels to lie on it. Does the mattress sincerely feel cool to the touch and give a satisfying chilling sensation for hot sleepers? Or will it sleep more temperature-natural? Do the materials retain body heat and keep you warmer? 

Other external factors affect what the temperature of a bed feels like to you, such as bedroom environment, the bedding you use and the pajamas you sleep in. At our mattress facility, we test beds in temperature-controlled rooms without sheets or bedding to analyze their construction and materials and explain how they affect the overall temperature of the bed.

Motion isolation

Motion isolation is a simple term for how well the mattress deadens movement across its surface. A bed with good motion isolation is essential for light sleepers or those sharing the mattress with a partner or pets. We test a bed’s motion isolation capabilities by having one expert lie on the bed while another flops around and switches positions. Does the person lying feel the movement through the mattress, or is it subtle and less noticeable?

For the second method, we set a glass of water on the edges, rolling toward and away to see if the glass falls or the liquid sloshes over. Typically, beds with dense memory foam perform the best in this category. More responsive mattresses tend to have worse motion isolation.

Edge support

Edge support refers to the strength of the bed’s perimeter, another important factor to keep in mind if you sleep with a partner or pets or tend to sleep on the edge. Testing the edge support involves analyzing how well the mattress holds its shape and structure when we sit and lie on the perimeter. Does it cave in and give the sensation we’ll roll off, or is it super sturdy and supportive? 

We also push down on the edges with our fists to observe how much it compresses under pressure. Many mattress brands add reinforcements around the edges — whether coils or firmer foams — to enhance the edge support. Having solid edge supports helps to create a stable and consistent sleeping surface across the entirety of the mattress.

Special features

Mattress brands often offer beds with special features, such as covers with cooling technology for hot sleepers or zoned support specifically for people with back issues like sciatica. We always test and review these additional characteristics to determine if they live up to the brands’ claims and to let you know which sleeper type would benefit most.

Learn more: How We Test Mattresses

The mattress characteristics that side sleepers should look for are different from those of strict stomach or back sleepers. Here are the main things to keep in mind if you favor your side when you sleep.

Firmness

Soft mattresses are typically more pressure-relieving than firm beds. With firm mattresses, the surface pushes back into your pressure points, which can cause pain and soreness and may even throw off the alignment of your spine. Softer beds are better for side sleepers (and combination sleepers who favor their sides) as they offer more contouring and cushioning beneath pressure points like your hips and shoulders.

Body type

In most cases, the heavier you are, the softer a mattress feels because you’ll typically sink deeper into the layers than a lighter individual, and vice versa. It’s worth mentioning that this is not always the case, as it largely depends on the bed’s construction, the materials used and the placement of its layers of foam and coils. 

Heavier sleepers over 230 pounds can usually get away with side sleeping on a firmer bed because it’ll feel a tad softer than for average or lightweight individuals. The reverse applies to lighter individuals under 150 pounds, who may want to opt for a true soft to medium-soft mattress so it won’t feel too firm.

Mattress type

The design and construction of your mattress directly influence how it feels and how long it lasts. Hybrid beds with coils tend to last longer than all-foam mattresses. Knowing what you want your bed to feel like will help narrow down your options. Do you like the sinking, contouring feel of dense memory foam that’s super slow to respond? Or do you like a bouncier mattress that’s more responsive and easier to switch positions? A soft and plush pillow top that feels like floating on a cloud? Or a mixed, neutral feel somewhere in the middle?

Sleeping position

We review four main sleeping positions on each mattress: back, stomach, side and combination. If you’re a strict side sleeper, a softer mattress is going to be key as firm mattresses are going to be too uncomfortable and unforgiving.

Back and stomach sleepers should opt for firmer mattresses that provide enough support to keep your spine neutrally aligned through the night. If the mattress is too soft while you’re lying on your back or stomach, you’re more likely to experience discomfort and even pain from the curvature of your spine and neck. 

Combination sleepers switch positions throughout the night. We typically recommend a middle-of-the-road medium (leaning into medium-firm at times) for combination sleepers, but it will depend on which position you spend the majority of your time in. 

Health concerns

If you suffer from pain — whether back, hip or joint — it’s important to keep this at the forefront while mattress shopping. Side sleepers with back pain should seek a bed that lands around a medium and offers a balance of support and pressure relief. If you have hip or shoulder pain, a softer mattress can help take some pressure off those sensitive joints.

At our expansive mattress testing facility in Reno, Nevada, our team of sleep experts is constantly reviewing new beds from all sorts of brands. We’re currently testing brand-new mattresses from brands including:

• Stearns & Foster
• Amerisleep
• Puffy
• Tuft & Needle
• Beautyrest

If you’re a strict side sleeper, we recommend steering clear of mattresses on the medium-firm to firm end of the scale. Beds that fall under this category include:

Saatva Classic: This mattress comes in three firmness levels, all of which we deem too firm for strict side sleepers. The plush soft model of the Saatva Classic could be doable for heavier side sleepers or combination sleepers who favor their sides, but we wouldn’t recommend the luxury firm or firm models.

Plank by Brooklyn Bedding: As the name implies, Plank is extremely firm. Plank Firm and Plank Firm Luxe are flippable, one side being medium-firm and the other a true firm — both sides much too firm for side sleepers. These mattresses are better for back and stomach sleepers who need substantial spinal support. 

DreamCloud Hybrid: The Mattress Smasher 9000 scored the DreamCloud Hybrid a 7.13 out of 10 on the firmness scale, confirming our consensus that it’s between medium-firm and firm. 

The numbers vary, but studies have shown that anywhere from 50% to 75% of people sleep on their sides. Aside from being comfortable, this sleeping position has certain health benefits, such as reducing the risk of sleep apnea and improving gut functioning. Side sleeping is also recommended during pregnancy (many providers specifically recommend the left side) as it can help improve blood flow to the organs and keep pressure off the liver. Having the right mattress is key, as side sleeping can have adverse effects if you’re lying on one that’s ill-suited for it.

There are a few things you can do to ensure that you’re sleeping soundly and comfortably on your side, including:

Use the right pillow

The pillow you use can drastically affect your overall sleep experience. Side sleepers typically need taller, loftier pillows that adequately support the head and align the spine and neck. A pillow that’s too flat will cause your head and neck to bend down and out of alignment with your spine, which can cause pain and discomfort.

Read more: Best Pillows for Side Sleepers in 2024

Add more cushioning

Using more pillows for extra padding is another way to increase comfort while sleeping on your side. Try keeping a soft and fluffy pillow between your knees to help relieve pressure on your back and promote better spinal alignment. You can also keep a pillow under your armpit if you have shoulder pain and need some additional pressure relief.

Consider a mattress topper

If your mattress is too firm but you’re not in a position to spend the money on a whole new bed, consider adding a mattress topper to your sleep setup. Doing so can change the firmness of your current bed, so side sleepers should look for a soft and plush topper.