Activity Trackers – Withings Pulse O2 Activity, Sleep, and Heart Rate + SPO2 Tracker for iOS and Android

Withings introduced the Pulse activity tracker back in 2013, delivering a small device with the ability to track steps, count calories, measure elevation, monitor your heart rate and track your sleep quality.

The company decided that wasn’t enough and has since introduced the Withings Pulse O2, with the added feature of being able to read your blood oxygen level – that’s Ox for oxygen, not oxen, as this tiny device is as far from a heavyweight beast as it could be.
We’ve been living with the Withings Pulse Ox over the last couple of weeks to see how it performs, where it thrives and whether the added feature puts it a step above its competition.

Small, simple design

Just like the original, the Pulse Ox is a thin 8mm rectangular device with rounded sides, measuring just 52 x 22mm face-on and weighing a mere 8g. It’s pretty tiny, as shown in our fingertip photos.

Withings Pulse O2 Activity, Sleep, and Heart Rate + SPO2 Tracker for iOS and Android

WARNING: This product is not waterproof or sweatproof; Activity tracking: steps, elevation, distance, running and calories burned; Wear it your way: clip and wristband included; Vital signs reading: ...

Made by: Withings, Available: In stock

The tracker is only available in black and the design is minimal in every way. A small Withings logo is present on the top of the Pulse Ox and there is also a small logo on the accompanying wristband and clip, but that’s all the branding you’ll find and the usual Withings subtleness is appreciated.

There is a small circular button on the top of the device, which is both the power and function control, and a Micro-USB port for charging it on the bottom. Not that you’ll need to charge too regularly: we managed to get around nine days life from the Pulse Ox on a single charge. That doesn’t quite match the suggested two-week battery life, but as it’s easy to charge and you only need to think about it roughly once a week it’s a generally good performance.

The front of the Ox has an OLED touchscreen with a 128 x 32 pixel display, providing blue metric-styled text that’s easy to read. Swiping sideways shows you various sets of data, including calories burned and your step count, as well as toggling to the heart rate and sleep monitoring mode display.

Flip the Pulse Ox over and slightly off-centre are four LED lights, used to measure heart rate and blood oxygen levels when a finger is placed and held there. The touch-responsive isn’t always on point so it can take a couple of tries to launch the heart rate feature or enter sleep mode though.

The Pulse Ox comes with a black or blue silicone clip that can be attached to your clothing, a black or blue silicone wristband with a metal casing that the device can slide into, or you can place it directly into a handbag, pocket or even a sock. You can also buy a pack of three brightly-coloured clips to turn your activity tracker into more of a statement.

It’s worth bearing in mind that the heart rate and blood oxygen level sensor is covered when the Pulse Ox is placed in the clips or the wristband, which makes accessibility impossible without removing it. This is annoying when exercising as it’s fiddly to check your stats – we would have liked a little more thought put into the accessories to avoid this.

We used the clip most as we found the wristband made the Ox bulky, despite the tracker’s small size. However, both options are very comfortable to wear and the extra bulk is useful when you’ve put the Pulse Ox at the bottom of your bag. The wristband features standard 18mm spring bars to customise the strap, but you’ll need a tool to adjust – there are none of the useful quick-release springs present, as per the Withings Activité.

Withings makes some lovely looking products and the Pulse Ox follows suit, but it is small and therefore easily forgotten about, meaning it’s come close to heading for a spin in the washing machine a few times.

Small is beautiful and the simplicity and cuteness of the Pulse Ox is something we really like, but finding it when it is misplaced is no easy task. Maybe it should have a proximity location tracker on it or something.

Activity tracking

Along with its design, the Withings Pulse Ox also follows in the footsteps of its predecessor when it comes to the activity tracking. It counts steps, measures distance, estimates calories burned and tracks elevation.

Elevation is a welcome feature as many competitor trackers lack an altimeter and therefore aren’t able to tell you how many feet you climb in a day, or represent your extra efforts like the Pulse Ox can. It makes this activity tracker that little bit more useful for those interested in more than just step tracking. Cue Kate Bush’s Running Up That Hill on repeat.

Speaking of step tracking, we trusted the step count and distance tracking more so on the Pulse Ox than other activity trackers we have tested recently. We had thePulse Ox, Withings Activité and Fitbit Flex on at the same time for a couple of weeks and the Pulse Ox consistently delivered data in the middle.

We thought the Activité was mean in awarding steps when we reviewed it (the same can be said for the cheaper Activité Pop), while we found the Fitbit Flex generous. As a small test, we counted our actual footsteps and compared them between the three trackers, all positioned on our right arm. For the 300 steps we took, the Pulse Ox awarded us 305, the Activité gave us 288 and the Fitbit Flex came in at 440.

Even so, the Pulse Ox comes with the same fundamental flaw as the Activité: you can’t change the 10,000 step goal. It’s one of the Pulse Ox’s biggest downfalls and although the feature is said to be coming soon, it isn’t here yet. By comparison theFitbit Flex not only allows you to change the step goal but also decide if you want steps, distance or calories as your main goal.

All is not lost for the Pulse Ox as one of the things we love most about it is the data is available on the device itself – you needn’t dig into an app each and every time. You can also see up to ten days worth of data by swiping the touchscreen within the category you want to know more about, which is great for motivation and helpful when monitoring your progress.

Both the Fitbit Flex and Withings Activité require an app to show the amount of calories you have burned or the exact number of steps you have taken (in the caseof Withings it’s iPhone only too).

It’s difficult to tell how accurate the elevation, calories burned and distance are overall but we found the calories and distance to be similar to a MapMyRun activity (a 13-mile walk resulted in 938 calories burned via Withings, 1015 via MapMyRun). There is no way of tracking specific activities, however, so if you are a keen cyclist or swimmer then you will find another activity tracker more useful. For those joggers and walkers the Pulse Ox is great – think of it like a posh pedometerthat has a few extra features.

Additionally, the Pulse Ox will analyse your running in real-time when you press the power button at the top of the device. You’ll be able to see distance and duration, which was a really useful feature when we weren’t running on a treadmill as it delivered the information we wanted to know instantly.

Heart rate and blood oxygen levels

To check heart rate and blood oxygen level, you first have to swipe through the functions using the top button until you reach the screen with the moon (sleep tracking) and the heart (pulse rate). Tapping on the heart will result in the Pulse Oxasking you to place your finger on the four LEDs at the back of the device, which light up red. It would be better if finger placement automatically triggered a read, rather than you having to swipe through all the various categories.

It takes 30 seconds to measure your heart rate and blood oxygen level but the PulseOx was temperamental when it came to delivering the results. There were times when it would simply present an “X” next to both stats, while other times it gave us our heart rate but not our blood oxygen level. It’s also worth noting the Health Mate app stores heart rate data history but not blood oxygen levels, which is odd.

Withings says monitoring your blood oxygen level is a way of assessing the overall efficiency of your respiratory function and while it might not be something of interest for every user, it’s (occasionally) there for those that want it. It was good to know how long it took us to recover after exercise, assuming a successful read was made.

A better strike rate would make the Pulse Ox a greater success. On the occasions when it did succeed in providing both heart rate and blood oxygen measurements, we weren’t convinced of its accuracy as our heart rate often seemed a lot lower than we expected, both resting and during exercise.

Sleep tracking

Many activity trackers offer the ability to monitor sleep patterns along with daily activity and the Pulse Ox is one of them. The tracker has to be placed in the wristband for it to work and, much like the Fitbit Flex, you have to tell it when you plan to sleep. Tapping on the moon symbol and then sliding a finger along the screen will kick-start the sleep monitoring, with a repeat slide motion telling it you’re awake.

The Pulse Ox will give you a breakdown of the night in terms of duration in bed, duration asleep, number of times you wake up, amount of light sleep, amount of deep sleep, amount of time you were awake and how long it took you to go to sleep, just like the Withings Activité does. Within the Withings Health Mate app, there is also the capacity to show your resting heart rate – but we never managed to get a reading for this.

The goal is to sleep for eight hours a night (as Withings claims an adult needs between seven and nine hours), but like the step goal, this sleep goal is unchangeable. This is frustrating as, like most busy adults, it means constantly failing, unless you are lucky enough to get eight hours every night.

Sleep tracking is a difficult thing to judge in terms of accuracy but the Pulse Oxdidn’t have any issues collecting the data, and it even seemed better than the Activité at realising when we had woken up in the middle of the night. The Pulse Oxdid seem better at knowing how long it took us to go to sleep however, most likely as the activity needs to be set active (which is irritating, as it’s easily forgotten) unlike the Activité. That said, we wore both devices on several nights and although their patterns were similar with the same length of sleep time, they were never identical.

There is no vibrating alarm on the Withings Pulse Ox, however, which is something we missed from the Activité and Fitbit Flex.

Withings Health Mate app

The Withings Pulse Ox will sync to your iOS or Android smartphone using BluetoothLow Energy and will transform the numbers into easy to understand graphs, accessible on both the Health Mate app and via web browsers. It can sometimes take a while to sync on its own but holding down the power button for three seconds will action a sync.

The Health Mate app has less significance with the Pulse Ox than it did with the Withings Activité as most of the data can be seen on the device itself, but it still has its uses, especially if you have bought other Withings products, such as the Smart Body Analyzer scales.

Everything from steps, calories burned, active calories, distance and elevation, toyour heart rate and sleep patterns are displayed in the Health Mate app in an easy to understand format on the dashboard. If you have the scales, your weight and air quality will also appear alongside the data from the Pulse Ox.

There is the option to set a weight goal and clicking on each of the categories will take you to a weekly graph, which you can change to a daily breakdown by selecting the three dots in the top right.

At the bottom of the dashboard is the option to organise your widgets so you can move sleep to the bottom of the dashboard, or activity to the top, for example, enabling you to customise what is most important to you.

If Withings could just add the ability to change the daily step and sleep goals, as well as allow you to have both the Activité and Pulse Ox under the same user, we’d be free of complaints. We had to set up a separate user with the same stats as us to use the Pulse Ox at the same time as the Activité and while you might not want two activity trackers, the Pulse Ox has some features the Activité doesn’t and vice versa.

If you need some extra motivation, the Health Mate app also enables you to team up with your friends and family, challenge them, and it will notify you when your ranking changes in the Leaderboard. You can collect activity badges and virtual milestones such as “330km O’ahu island” when you push yourself and there is also the option to set-up personalised coaching and healthy reminders.

Withings is a fantastic platform, especially when linked to partner apps such as MyFitnessPal so you can monitor your nutrition against your physical activity. There are a few flaws that need ironing out for the Health Mate to achieve perfection but it still raises products like the Pulse Ox from good to great.


The Withings Pulse Ox is a small, simple and sophisticated solution to health monitoring. It’s versatile when it comes to wearing it and it does everything you want an activity tracker to do, from counting your steps and distance, to monitoringyour heart rate (but not in real-time) and sleep patterns.

The difference the blood oxygen level monitoring adds compared to the original device doesn’t make a huge difference, though, and more often than not we couldn’t get a reading anyway. It also doesn’t deliver on the promised two-week battery life, the 10,000 step daily goal can’t be changed, there’s no way to track specific activities, and some of its data accuracy is questionable.

Overall the Withings Pulse Ox is a fantastic activity tracker for its £100 asking price. Its defining oxygen feature is unlikely to be the primary reason to buy it, but coupled with all its other functions – including the altimeter to measure elevation and decent accompanying app – it’s a cracking small-scale product that won’t disappoint those who run or walk as their primary activity.


Small, nice design, plenty of ways to wear it, great app platform, data available on device, step tracking and distance seemingly accurate, sleep tracking not flawless but useful


Heart rate and blood oxygen level sensor temperamental, can’t alter step or sleep goals, can’t have more than one Withings activity tracker linked to an account

Withings Pulse O2 Activity, Sleep, and Heart Rate + SPO2 Tracker for iOS and Android

WARNING: This product is not waterproof or sweatproof Activity tracking: steps, elevation, distance, running and calories burned Wear it your way: clip and wristband included Vital signs reading: instant heart rate and blood oxygen level Sleep monitoring: sleep cycle analysis, wake-ups, total...

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Product Dimensions

0.3 x 0.9 x 1.7 inches ; 0.3 ounces

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5.6 ounces (View shipping rates and policies)

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Currently, item can be shipped only within the U.S. and to APO/FPO addresses. For APO/FPO shipments, please check with the manufacturer regarding warranty and support issues.

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I liked it, for the two months that it worked. Be aware if you buy this product that it is not warrantied against SWEAT. I bought it to replace the Fitbit Force that got recalled, and I found the Withings to be pretty accurate but have less functionality and be less consumer friendly...for instance, if I forgot to wear the Fitbit I could add in my exercise on the app and it would calculate the steps it missed, but that wasn't possible on the Withings app. The real issue came when the device stopped working. After several emails back and forth with the company, they said they would send me a form to return it, but they also sent another form that said the device has a sensor inside and if it has detected any humidity, from any liquid including water or sweat, that the warranty is not valid. Well, I wore the thing to run, like I wore my Fitbit, so I guess it was the sweat that killed it. Not really a good option for exercise tech if it can't handle humidity or sweat.
September 8, 2014
I recently purchased the new Withings Pulse O2 activity tracker, (FYI now available for purchase on Withings website) after having to stop using the Fitbit Force, which was taken off the market due to a small percentage of users experiencing an allergic reaction to a metal piece that comes into contact with your skin. (Unfortunately after a few months of use I was one of those people.) I did not own the previous Pulse device.For a quick, short review, the Withings Pulse O2 tracks steps/feet climbed/miles traveled/calories burned, and can determine your heart rate, blood oxygen level, and sleep, which can all be displayed on the device along with the date and time. It can be synced wirelessly via Bluetooth, and you can set goals on the app. I enjoy the device; the 4 out of 5 start review is due to the material the band and clip are made out of, a soft, rubber material that attracts a lot of dust and lint. In comparison to the Fitbit, cannot track steps while in sleep mode or notify you when you've reached your goal. Those are not major reasons for me to stop using it, but since I've used different devices in the past, I have something else to compare to. I recommend this device to anyone looking to own an activity tracker that tracks the info listed, it is easy to use and sync. Below is a more detailed review, breaking down the different tracking options and comparing them with the other devices listed in the summary.I am a Fitbit fan; I have owned most of the different versions of the Fitbit. (Original Fitbit/Fitbit One/Flex/Force) For the most part all of the Fitbit's track the same data, the original and One are clips, and Flex and Force are armbands. The Original, One, and Force display the info on the device, Flex syncs to your phone or computer where you can check the data. The Flex will show "dots" on the screen to show your progress to what you've set as your goal, and will notify you once you've reach it, which is how the Nike Fuel band works.The Withings Pulse is very similar to the Fitbit, with the addition of being able to check your blood pressure and blood oxygen level. All of this info is displayed on the device, and you can sync by either plugging it into your computer via a cable or sync to your phone via Bluetooth. I recently received the Withings Pulse O2, so I only have a few days experience with the device, but that has been enough for me to compare it to different trackers I have owned.DEVICE FEEL:The Withings band and clip are made out of a soft, rubber material. That is one of the reasons I gave it 4 out of 5 starts. The rubber material is the type that attracts everything, dust, lint hair. And I have very small wrists and the band, even on the smallest setting, is still slightly big.The Fitbit Flex and Force is a more rigid, flexible rubber material, and uses a plastic clip to secure the band. You also select a size when purchasing, but similar to most wristbands, it has many slots to secure the clip. I found the Fitbit Flex/Force to be the most comfortable and secure device. The Original and One are clips and do not come in an armband options, but you are given a fabric wrist band to insert the device if you want to track your sleep.The Nike Flue Band is a very rigid, slightly flexible rubber material. I did not like the feel of the Fuel Band; it was too rigid and did not fit comfortably because of this. The Withings and Fitbit bands are flexible enough to wrap around your wrists comfortably, the Fuel band holds its shape.The Striiv is a device that you can wear many ways, you are given a clip, strap, and wrist band to wear. I have only used the clip; the device does not track sleep so I have never worn it in bed. It is larger than the other devices, but for me has been comfortable enough to clip on the inside of pants pockets.TRACKING STEPS:All of the devices track steps, the Withings, Fitbit Original/One/Force, and Striiv all display this info on the device itself. There isn't much to say here, one reviewer of the Withings mentioned it did not track as many steps as the Fitbit, I am currently using the Withings/Fitbit/Striiv devices and so far the Withings device is tracking the most steps. Striiv has the least amount of steps, which makes sense because I do not wear it at night, and I start using it once I am up and ready to leave the house. The Withings and Fitbit devices only come off when showering, so I am tracking those lost steps in between. As far as the Withings and Fitbit being off on steps, I'm not sure yet why, maybe more use will give me more info to determine the offset.The Nike Fuel Band and Fitbit Flex do not display this info on the device, but it is tracked and can be viewed via the apps once the data is synced.TRACKING STEPS/FEET CLIMBEDTo note, most of the devices allow you to set what unit of measurement you want to use when tracking. All devices except for the Nike Fuel band track this information.Withings tracks feet climbed, Fitbit tracks steps climbed, and Striiv tracks equivalent stairs climbed. At the moment all three show different data, which I am not sure why. I would have to do more research between the devices to determine the difference.The Fitbit Flex does not display this info on the device, but it is tracked and can be viewed via the app once the data is synced.TRACKING MILES:All devices other than the Nike Fuel band track miles traveled and you can set what unit of measurement you want. They are all relatively close, similar to the steps being off, Withings shows the most and Striiv is showing the least.The Fitbit Flex does not display this info on the device, but it is tracked and can be viewed via the app once the data is synced.TRACKING CALORIES BURNED:All devices other than the Nike Fuel band track calories burned. They all show different numbers, the Fitbit shows the most because it calculates an assumed number of burned calories when sleeping. Striiv shows more than Withings, which is odd since it shows fewer steps taken. I would have to look into whether it also calculates an assumed number from sleep as well.The Fitbit Flex does not display this info on the device, but it is tracked and can be viewed via the app once the data is synced.TRACKING SLEEP:I read some reviews of the previous version of the Withings Pulse that the sleep data is more informative than the Fitbit, from my experience it is about the same. It will show you deep/light sleep and any times you were awake. Withings looks to be slightly more sensitive to movement, but other than that the tracked data is very close.With Withings, you need to set the device itself to "sleep mode" to being tracking the data. When it is in sleep mode, it will not track any steps taken if you wake up at any point and get out of bed. I did run into trouble trying to set the device to sleep mode. I read on their website to restart the device, and that did resolve the issue.The Fitbit does not have to be set in a sleep mode, you can either use your phone and indicate on the app that you have "started" sleep, and when you wake you indicate that on the app, or set the time you got in and out of bed manually on the app. (phone or computer) Once you sync your device it will calculate your movement and determine the same info, along with tracking any steps taken if you do wake up and get out of bed. It will also calculate calories burned during sleep, which is really just an assumption from the personal data you've entered when you receive your device.The Fitbit Flex does not display this info on the device, but it is tracked and can be viewed via the app once the data is synced. The previous version of the Nike Fuel band I owned did not track this information, according to Nike's website they have a newer version that does.ADDITIONAL DEVICE INFORMATION:Withings can also determine your heart rate and blood oxygen level. On the device, same place to set sleep mode, is a heart. If you press the heart it will tell you to place your finger on the device, there are sensors on the back of the device. Within a few seconds it should display the info. So far I have been having trouble getting the device to read that info, it worked a couple of times, since then it gives me X's to state it could not determine my heart rate and pulse ox. I am not too concerned about tracking this info, but I may contact customer service if the problem continues.The Fitbit Force tracks "Very Active Minutes", which can be helpful if you are looking to track the amount of minutes you may have exerted yourself. (Recommended 30 minutes a day of vigorous activity) One additional feature I like about the Fitbit is that it will notify you if you reach your goal by gently vibrating. I haven't used it, but you can also set a silent alarm, it will gently vibrate to wake you.The Striiv activity tracker is very unique in comparison to any other activity tracker. If you are interested in learning more about it, check out the following link Striiv Smart Pedometer, Accessory Bundle I have also posted a review about this product as well. There is too much detail to get into here about that tracker, but it has many other features that Withings and Fitbit do not have.APP INFO:All of the trackers have applications that allow you to see your data that has been tracked. You can either view it on a smartphone or computer, and these applications are very different from one another.The Withings and Striiv applications are very similar; you have a dashboard that shows you each of the items tracked. This is all you can do on the app with Striiv. With Withings you can download your information, look at previous day's information, manually enter your weight/height/BP/Pulse Ox, and earn badges.Fitbit allows for much more on their application. You can track your food and water intake, enter additional activity, enter heart rate, BP and glucose info to track, has a journal option to note any additional info, and the beta version of the dashboard now has a "Trainer" option, which is a 12 week plan you set to help keep you motivated.Between all of the devices, I feel the Withings Pulse O2 and Fitbit Force are very comparable, the Fitbit Flex tracks the same info but it is not displayed on the screen. I am a Fitbit fan myself, but so far have enjoyed using the Withings device. It is tracking the same information I was tracking previously with Fitbit, with a few additions. For what I am looking to track, it works great and fits great. As stated earlier, the 4 starts is for the type of rubber material they decided to use, not being able to track steps while in sleep mode, and not being able to notify you when you've reached your goal.
April 29, 2014
I recently purchased this activity tracker directly from Withings, and I am less than impressed with it. I am a dedicated walker (approximately 5 miles at a 17 minutes/mile pace, 12,000 steps each day). I have used the Jawbone UP for the past several months, but decided to try something else due to apparent quality control issues with the UP (they break frequently). So far, I find that the Withings Pulse O2 counts only about 40% of steps actually taken and distance covered. This is completely unacceptable for my purposes, so I am planning to return the item for a refund.UPDATE: I have found that how the device is worn significantly affects the accuracy of step counts. I repeated the same walk (route, distance and pace) on two successive days. The first day I wore the device strapped to my wrist and got the following counts: 5,070 steps; 2.13 miles, 286 calories. The next day I wore the device clipped to a pocket near my waist and got the following counts: 11,702 steps; 5.37 miles, 626 calories. The second day counts seem about right. The manufacturer provides no specific recommendations, but apparently the wrist strap should be used only for sleep monitoring. In light of this finding, I have increased the product rating and will continue to evaluate this activity tracker.
April 27, 2014

Activity Trackers – Withings Pulse O2 Activity, Sleep, and Heart Rate + SPO2 Tracker for iOS and Android
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