What are under the mattress sleep trackers and should you buy one?

Man liftingupa mattress to insert a sleep tracker underneath
(Image credit: Getty Images)

Under-mattress sleep trackers are a simple and effective way to keep an eye on your night-time statistics. Unlike wearable sleep trackers, under-mattress sleep trackers give you extra information on your sleep quality and duration without the potential irritation of having to wear anything directly on your body. 

The best mattress for you is the one that most effectively lulls you into a deep and comfortable slumber — and the best under-mattress sleep trackers are those which can provide accurate data surrounding just how much sleep you're getting (or not, as the case may be). 

In this guide we’ll bring you a clear explanation of exactly what under-mattress sleep trackers are, and how they differ from regular sleep trackers. We’ll explore how they work, how much they cost, and the pros and cons of using one. Finally, we’ll walk you through what to look for and avoid when you’re buying an under-mattress sleep tracker for your home. Ready? Let's get started. 

What is an under-mattress sleep tracker? 

Unlike smart mattress covers, which sit on top of the bed, an under-mattress sleep tracker is designed to fit between your mattress and the base of your bed – this is why many of them are shaped like small mats. 

The best smart beds and under-mattress sleep trackers are packed with advanced sensors that can track your sleep patterns, including your breathing, movements and heart rate. Information from the tracker is then sent to an accompanying app and used to figure out your sleep stages – like light, deep and REM sleep

The app associated with an under-mattress sleep tracker will also show you insights about your sleep quality and duration, as well as allowing you to monitor sleep trends over time so you can spot any recurring patterns. 

Man puts a sleep tracking mat under mattress

(Image credit: Getty Images)

Under the mattress sleep trackers: Pros

It's all about the information. If you've ever woken up feeling awful with no idea why, you'll understand that a little extra data could come in very handy.

Under-mattress sleep trackers are a great choice for anyone who wants to understand more about the quality of their sleep. They collect detailed information and use it to offer insights about your sleep patterns, the sleep stages you move through during the night, and how many times you get up to use the bathroom. 

Woman checks sleep tracking data on tablet

(Image credit: Getty Images)

You can then analyze this data, use it to spot trends, and make changes to your lifestyle habits or sleep environment which might make things better. 

Many people also choose under-mattress sleep trackers over smart devices that are worn on your wrist or on your finger because they’re unobtrusive, which means they won’t be uncomfortable when you’re trying to nod off. 

Under the mattress sleep trackers: Cons

One of the key drawbacks of an under-mattress sleep tracker is accuracy. Given that there's a mattress between you and the device, the results may not be as accurate as those from something worn on your wrist or on your finger. This applies to important health metrics, like heart rate or body temperature, because the sensors aren’t on your skin. 

But some under-mattress sleep trackers might also have a hard time detecting movements or even differentiating between different people in the same bed. This is why it’s important to do your research and look for the best under-mattress sleep tracker for you: one that’s already been tested for its accuracy and has plenty of positive reviews online. 

Do under-mattress sleep trackers work with all beds?

Most sleep tracking mats and under-mattress sleep trackers work well with all types of mattresses. However, it is worth considering that some of the more thick and dense mattresses on the market could affect the sensitivity of the sensors, leading to less precise data. What’s more, memory foam mattresses are at a disadvantage. They absorb movement so well that they could affect the tracker’s ability to accurately pinpoint sleep cycles

We recommend that you check the specifications of the under-mattress sleep tracker that you’re considering before you buy it. However, most of the best under-mattress trackers are designed to accommodate all sorts of beds, mattresses and homes, so you probably don’t have anything to worry about. 

How effective are under the mattress sleep trackers?

Both under-mattress sleep trackers and wrist- or ring-based sleep trackers are effective ways to track sleep, but they have different benefits. Wearable sleep trackers could be more accurate because they’re placed next to your skin, allowing for more precise monitoring of metrics like body temperature and heart rate. 

Sleeping woman wears a sleep tracker on wrist

(Image credit: Getty Images)

On the flip side, under-mattress sleep trackers are non-invasive, and many are designed to compensate for thick mattresses. For many people the decision will come down to personal preference. If you know you’ll find wearable sleep trackers uncomfortable and likely to disturb you throughout the night (or if you forget to wear it entirely), then an under-mattress sleep tracker is your best choice.  

How much do under-mattress sleep trackers cost? 

Like most devices for your home, there are several different under-mattress sleep trackers and sleep mats available to suit different budgets. For example, one of the most popular under-mattress sleep trackers is the Sleep Analyzer, from wellness tech brand Withings. It currently costs $129.95/£129.95, bringing you easy set-up, advanced tracking, and home automation functions. 

In comparison, the Beddit sleep tracker is currently available on Amazon in the UK for £67.49, but it’s older and less advanced than the device from Withings – and it’s no longer available in the US. It’s worth remembering that although it seems like the same tech, not all sleep tracking devices are created equal. 

A person puts a Withings sleep tracking device under a mattress

(Image credit: Withings)

Should you buy an under-mattress sleep tracker? 

An under-mattress sleep tracker is a good option if you want to track your sleep and monitor your sleep patterns over time with the tracker’s accompanying app.

It’s worth considering, though, that there is much more choice in the wrist-based sleep tracker space, and we're even starting to see a number of smart rings that track sleep. They might even work better, considering their proximity to your body. 

However, under-mattress sleep trackers are ideal if you find wearable tech uncomfortable and think it could lead to a restless night, or you want a set-and-forget sleep tracking solution. Ultimately, the question of whether you should buy an under-mattress sleep tracker comes down to the data you want to collect and your personal sleep preferences.

Becca Caddy

Becca has written about homes, lifestyle and tech for brands such as TechRadar, T3, The Guardian and many more. Her first book, Screen Time, came out in January 2021 with Bonnier Books, within which she also explores how screen use affects sleep. For Tom's Guide Becca writes about sleep health and techniques, with the aim of helping readers to sleep better each night.