Withings Sleep Analyzer review

It's big on data – but we're not not sleeping any better
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Withings Sleep Analyzer
By Withings
The Withings Sleep Analyzer delivers good solid data, on the whole, without having to wear anything to bed. It’s generally reliable and offers some of the best sleep apnea insights on the market. However, we feel the lack of education and ability to use t to make meaningful changes to your sleep will be disappointing for those that have forked out for a dedicated sleep device.

  • Data seems to be accurate
  • Clean, clear app
  • Sleep apnea well handled
  • Some wake up logging issues
  • Lack of actionable advice
  • Doesn't add much over general sleep devices

If you’re looking to get a detailed picture of your sleep, the Withings Sleep Analyzer may well catch the eye. A dedicated sleep sensor that fits under your mattress, it’s been medically validated to detect sleep apnea, as well as provide deep insights into what happens in the time between going to bed and the alarm going off.

As we focus on our health, good sleep is increasingly being put in the spotlight. And there’s no shortage of devices that claim to offer analysis and data.

Indeed, sleep apnea is of particular interest to the wearable tech industry, with most new devices from the Fitbit Charge 4, Versa 2 and even Huawei Watch GT 2e now packing an SpO2 sensor. Sleep and sleep apnea is also said to be a target of the forthcoming Apple Watch Series 6.

It's received medical device marking from the CE for use in Europe and the UK – but crucially will not yet be offered in the US. The older Withings Sleep is still available there, and there's no word if or when the FDA will approve the Withings Sleep Analyzer.

So is buying a dedicated sleep monitor worth it? And what did we learn from a month with the device? Read on to find out.


Withings Sleep Analyzer review

The Withings Sleep Analyzer itself is a pretty simple affair, and a tried-and-tested design that Withings has been using since the Aura back in 2014.

It’s a soft mat that slips under the mattress of your bed, positioned where your chest would be. From here it will keep tabs on movement, breathing and heart rate using precision hydraulic sensors. Impressive stuff.

The mat fits one person, so it's the width of a single mattress or half of a double. If you want to track two people, you’ll need two mats.

It’s so thin there’s no way you’ll notice it under a mattress, and it’s fine to use on beds with slats. We positioned the cardboard sleeve from the packaging under the sleep mat itself just to ensure a secure fit.

The Sleep Analyzer has a long cable, so that shouldn’t interfere with positioning either. In fact, our plugs were on the other side of the bed, and there was no issue reaching.

Sleep data

Withings Sleep Analyzer review

In terms of tracking and data collection, the Withings Sleep Analyzer offers a pretty complete set of sleep stats, and utilises a helpful traffic light system within the app to help guide you through your data.

The key areas are sleep duration, sleep stages (deep, light, REM, awake), sleep depth, interruptions and average sleep heart rate. That’s the kind of stuff you’ll get from pretty much every sleep tracker out there.

Then you get the extra stuff. Snoring events are tracked using a microphone, and sleep regularity is logged – which is the time you go to sleep and wake up tracked across the week. Good, healthy sleep can be achieved by the same bed time/wake up times, so it’s nice to see that included in the mix.

And then there's the main event: sleep apnea. Sleep apnea is a condition that affects breathing during sleep, and thus the oxygen levels in the body. If you have full-blown Obstructive Sleep Apnea, it can be pretty debilitating. Most people that suffer don’t know they have it, so detection is certainly a useful feature for anyone.

Thanks to CE validation, sleep apnea data is front and centre – rather than hinted at by the tracking of blood oxygen as you’ll find on Fitbit and other devices.

It’s also not presented as a single yes/no for sleep apnea, but a scale from mild, moderate to severe. The key message is that everyone will have apneic events, so the Withings will give you insights into when those are, and when you should worry about them.


Withings Sleep Analyzer review

Reviewing sleep data is close to impossible, unless you’re in a sleep lab – so you’ll have to place a certain amount of trust in the studies that have validated Withings’ tech. However, we tested alongside the Fitbit Charge 4 – and there was plenty of synergy between the two.

Both devices generally mapped sleep stages with similar patterns, and spat out very similar sleep scores through our test period. By seeing such similarities between two validated devices, we’re inclined to trust this data.

The Withings Sleep Analyzer, however, was much harsher on deep sleep duration, which we’ll come back to shortly.

While sleep stages seemed to be accurately tracked, we were a little troubled by some aspects of the Withings Sleep Analyzers’ accuracy.

A few times long lie ins were also recorded as sleep – and worryingly – as REM sleep.

We found that data was often slow to be introduced into the app. You could look at your data when you wake up (a natural time to peruse your sleep) and find half a night’s sleep, usually tracked until a 4am toilet visit, with the traffic light system flashing warning signals like Chernobyl – only for it to be updated in full later, with a sea of green tranquility.

Heart rate accuracy was in line with Fitbit’s, with both showing similar data across the night. Fitbit doesn’t provide an average heart rate for your sleep, but does sample resting HR at night, and these were both logged within 2bpm.

And then there’s sleep apnea and snoring – which is possibly the best implementation of sleep apnea detection we’ve seen. We had a few snoring events logged, though only fleeting flashes.

However, we did border into moderate sleep apnea, which then triggered a flag to take one of two surveys, that are found in the app. We answered a questionnaire of yes/no answers, and it was determined that our chances of actually having Obstructive Sleep Apnea was low.

We were able to use Withings snoring data to answer one of the question – so this all seemed to work well together. And it’s something we’ll be keeping an eye on.

The app, analysis and education

Withings Sleep Analyzer review

So far so good – bar the squiffy wake up data. We’ve always been fans of the Withings Health Mate app, and use it for weight tracking via the smart scales. It will also suck in movement and step data via Google Fit or Apple Health, so there's more than just sleep data to look at in the app.

However, the sleep data presentation has left us a little cold on the Withings Sleep Analyzer.

We liked the overview of each night’s sleep, and the traffic light system works well. Each piece of data has a red, amber or green dot to show you what you need to focus on.

The graphs are also good, clear and well structured – and it’s easy to tap a section of sleep to see the time scale it occurred.

But there are some aspects that have been bettered elsewhere, on non-dedicated sleep devices – and that shouldn’t happen.

While you can easily witch your sleep trends by day, week or month at the bottom, each night’s sleep on the Withings Sleep Analyzer feels isolated.

We found the way Fitbit shows all your sleep scores over a week more motivating – including a preview of the sleep graph – so you can easily correlate a week of poor sleep and make a conscious decision to be better.

And that’s another part of the Withings app that disappointed. It’s good informing you which elements of your sleep weren't up to scratch – but less adept at coaching you to make improvements.

While sleep apnea education, surveys and explanations dominate the app, there’s pretty much nothing around general sleep health. There are minimal suggestions and training for to understand aspects sleep generally, but not a lot of actionable points.

An example was how we struggled to get enough deep sleep, according to the Withings app. It constantly displayed a red flag to say we weren’t getting enough – but offered precious little to suggest ways to improve. It's only suggestion was promoting sleep consistency, but we were already scoring maximum for that. It was frustrating to get poor sleep depth night after night, but not be offered ways to improve things.

There’s also a lack of content on the platform. There’s one mindfulness program, that doesn’t implicitly mention sleep. Rival platforms offer breathing exercises or pre-bedtime routines. Health Mate leaves you with the data, to a certain extent.

It also does less to put data in context. In the Fitbit app you can benchmark your sleep data against people of your age and gender. Withings’ sleep data feels – and we use the word again – isolated.

How we test

James Stables


James is the co-founder of Wareable, and he has been a technology journalist for 15 years.

He started his career at Future Publishing, James became the features editor of T3 Magazine and T3.com and was a regular contributor to TechRadar – before leaving Future Publishing to found Wareable in 2014.

James has been at the helm of Wareable since 2014 and has become one of the leading experts in wearable technologies globally. He has reviewed, tested, and covered pretty much every wearable on the market, and is passionate about the evolving industry, and wearables helping people achieve healthier and happier lives.

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