Gadget review: The Withings Smart Body Analyzer

In the coming weeks we’ll be reviewing self-measuring gadgets that we use. We will tell you what we like about them and what not.

Let’s kick-off with the Withings Smart Body Analyzer or WS-50.

Like it’s smaller brother, the WS-30, the Smart Body Analyzer is a Wi-Fi scale but with more functions. In addition to your weight, it also measures

  • Your heart rate
  • Your body-fat ratio
  • The temperature and CO2-levels in your room


The WS-50 sells at $50 more than the WS-30. Is it worth the extra money?

I’ve been using it for seven months. Here’s what I like about it:

withings_mobile1. I love the automatic Wi-Fi-sync. It works like a charm. As soon as I’m off the scale I can look at my data on the well-designed Withings mobile app (image to the right).

2. I like the fact that it measures CO2 levels and the room temperature: it gives me two more variables that may influence my sleep. As a self-measuring freak I am always looking for connections and the more data I get, the higher the chance that Addapp shows me a surprising revelation.

3. The resting heart rate is an important health indicator: I want to measure it every day. The best moment to capture it is in the morning, right after waking up. I can think of no more comfortable way to do that: I just have to hop on the scale, wait a few seconds and voilà: there’s my heart rate…

This is the first in a series of product reviews here on the Addapp blog. To stay up-to-date and make sure you don’t miss out on the next posts, make sure you follow us on Twitter and like our Facebook page!

And that brings me to the things I don’t like

1. It’s a shame but the heart rate just isn’t accurate. I compared the results with Withings blood pressure device: the WS-50 is up to 20 beats wrong, making the function effectively useless.

2. The WS-50 isn’t portable. True, the WS-30 and all other scales have the same problem but I wish I could roll it up and stuff it in my bag. I want to measure every day and I have to enter the data manually when I am on the road. That’s inconvenient even though I don’t travel that often.

3. The body fat measurement is another promising function that doesn’t work well in practice. The major problem here is the software. You have to tick a personal profile on the app. But look at the choices you get:


These choices sound more like software versions than body types. As weird as they are, I could live with them if I knew how to pick the right one. But there’s no such explanation. And as I get very different results in each setting, I can’t even start to make sense of it all.

So, would I recommend forking out the extra $50?

I’d be very happy with the WS-50 if the heart rate and fat mass measurements worked.

Not that I am unhappy: the scale measures my weight accurately and syncs ever so well. But, I assume the smaller brother does that just as well. The only reason to upgrade would be to measure temperature and CO2 in the room – is that worth 50 bucks? I don’t think so.

Have you used the Withings Smart Body Analyzer? We’d love to hear your thoughts in the comments. 

CEO & Co-founder of Addapp. I love tracking, coffee, anything cooked by my mom, startups, and quantifiedself.

8 comments… add one

  • I have been using the original Withings scale for a couple of years now and I am really satisfied with it. I also thought about upgrading to the WS-50 but since the scale resides in my bathroom I don’t care for the CO2 there. One cool thing about the new scales though is the ability to sync via your phone using Bluetooth.

    • Indeed the bluetooth sync is something I really enjoy! I simply go on my scale in the morning and it simply syncs to the iPhone. It takes all the friction of manual logging or plugging in/out etc.

  • My wife got me this scale for my birthday back in December and I have to disagree with you about the HR accuracy. I find it to be as accurate as my Life Source BP cuff (I have HBP). As for the body fat composition, I don’t even think the TANITA BC-1000 has nailed that yet.

    • Thanks Eric, regarding the heart rate happy to hear it works for you! I tested the heart rate from the smart body analyzer with the Withings blood pressure device which gives the heart rate metric as well for 9 days straight. In most cases the difference was 20 beats per minute higher with the smart body analyzer.

      • 20 beats is pretty dramatic. If you bought the scale, I would exchange it.

        • I did buy it and might actually contact them to exchange it :-)

  • Hi Kouris, thanks for sharing your analysis! I have the WS-30 and I’m very satisfied with it. It does exactly what I’m looking for. I also have the Blood Pressure Monitor and measure every morning just when I enter the office. Don’t know if that’s the best timing but we share it in the team at this moment. I saw you measured blood pressure too; when?

    • Hi Philippe, thanks for your comment! What I do is I measure my blood pressure with the Withings blood pressure monitor every morning right after I wake up. I take a couple of minutes of deep breath to relax and I measure myself. In my opinion, and according to articles I’ve read, that’s the best way to do it. Maybe you can do it as well in this way! In any case, I am planning a gadget review on this device as well so I’d love to hear your thoughts when we publish it!


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