Samsung Outlines Galaxy Watch4: First New Google WearOS Watch–Full Details

2021-08-11 (53)

Today, Samsung announced their Galaxy Watch 4, which is the first watch to utilize the new Google + Samsung variant of Wear OS. This new operating system (or, slightly rebranded one) allows access to the Google Play store, while Samsung says it also brings the “best of” Tizen to the table as well (Samsung’s existing smartwatch platform).

Today, Samsung kicked off their ‘Unpacked’ event straight with the watch itself. This is notable, as the watch is typically slotted later into most major presentations, whereas this time the event literally opened straight into the announcing of the watch and functionality. And virtually 98% of this presentation focused on health and fitness.

Samsung’s added a slate of new health/fitness features, including body composition monitoring using just two fingers touching the watch. In fact, they went to extraordinary lengths to try and explain this and their claimed accuracy during the presentation. Seriously, nobody has ever spent so much money on advanced computer graphics for a detailed watch sensor accuracy video, than Samsung just did. Atop that, the company has added both snoring tracking with blood oxygen tracking together, from a data visualization standpoint.

So, let’s dive into all those features a bit more.

Galaxy Watch4 Fitness Specs:

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Since you’re reading this site, you probably know it’s sport and fitness focused. Thus, those are the things we’re gonna focus on here. Not that it matters too much, since Samsung literally didn’t mention a single non-sports feature, aside from Spotify access and new buttons, during their presentation. And don’t worry, I’ll cover the two button thing in a second.

To begin, the watch is called “Galaxy Watch4” (no space between Watch and 4, officially), and will be available for pre-order today, with delivery Aug 27th. Prices are $249 for the base unit, and $349 for the ‘Classic’ styled unit. Effectively, the Samsung Galaxy Watch Active line becomes the ‘base’ unit, while the ‘Classic’ unit is like the regular Galaxy Watch, complete with the rotating bezel.

Speaking of branding, officially Samsung says that the operating system is “Wear OS powered by Samsung”. It’ll be interesting to see how that’s branded on other non-Samsung watches. Note that Samsung says that a Galaxy phone is not required for usage of the Galaxy Watch4.

Focusing on all the health and fitness things, here’s the quick bulletized version of what’s changed:

– Brought optical heart rate sensor close to wrist, to increase heart rate sensor accuracy
– Changed optical heart rate sensor system
– Snoring tracking + sleep blood oxygen levels combined together (requires phone on bedside table though)
– Added body composition measurement for things like body fat and muscle mass
– Expanded ECG regions/support
– Access to Google Wear OS sports apps like Strava, Adidas, Swim.com
– Newly “enhanced” compass for use in Google Maps

First up is a new optical heart rate sensor and underlying system, which they specifically noted they moved closer to the wrist for better accuracy. Samsung has historically lagged behind others on optical HR accuracy, and one of the best ways to increase accuracy is to get rid of potential light leakage between the wrist and the sensor.

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From an apps standpoint, Samsung highlighted a few sports ones specifically, including Strava, Swim.com, and Adidas. And then noted that apps could be accessed from the Google Play store. Google Maps was also highlighted as well as the various core Samsung apps like Samsung Pay.


Samsung highlighted that they’ll be doing sleep blood oxygen tracking combined with snoring tracking, and specifically, overlaying that data together. The snoring tracking requires though that your phone be on your bedside table, and then the two pieces are combined together.

Interestingly, Samsung mentioned that users checked their sleep stats a total of 800 million times over the past year. That’s actually not that impressive of a number in context for it, given that’d be an opportunity of 365 times per year, that means if we’re talking 10-20 million watches, people actually aren’t using this functionality much (on 2 million watches, that’d mean everyone checks daily, on 20 million watches, that’d mean only 1 in 10 people check daily). You can mix and match those stats a million ways, but I thought that was curious.

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The headliner feature for the Galaxy Watch4 was clearly body composition measurement. Samsung spent a ton of time in the presentation explaining how it worked, including an exceptional amount of technical details and jargon (which, I loved).

The new feature simply requires users to place two fingers on the two buttons on their watch for 15 seconds, and then will use electrical impedance (BIA) to measure your body composition (such as body fat and muscle mass). This is similar in technological concept to most body composition scales that we’ve seen for decades, except, that Samsung says it’s actually accurate (I’ve shown many times that body composition scales are mostly a crapshoot).

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Interestingly, Samsung talked a while about how they’ve been trying various technology concepts related to body composition for a decade, including everything from wristband sensors to TV remotes.

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Samsung talked about how, typically speaking, the smaller the sensor pads (electrodes) for electrical impedance, the less accurate they were – thus why they never really found the accuracy they were looking for. So when scaled down to small watch buttons, they said that things went down the toilet.

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Instead, the company says their new system is far more complex, using a series of switches that checks and re-checks measurements 160 times a second, for a total of 2,400 times over the course of the 15 second measurement period. Calculating and recalculating. Seriously, I can’t overstate how somewhat impressively Samsung spent on trying to explain this feature or the graphics.

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The end resultant are body composition measurements that Samsung says are 98% correlated with traditional DXA scans. That’d be a very impressive feat, if indeed accurate. But they seemed to back this claim up with not only fancy stock footage of people in laboratories, but also notably an image of the Pennington Biomedical Research Center, which focuses on areas like this.

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As always, I’ll be interested to do some independent testing of this, perhaps getting a few volunteers in the Amsterdam area. That of course depends on world conditions allowing, but I’m more optimistic than usual on this one.

Next, Samsung is expanding their ECG accessibility to more countries (this is mostly just a certification related thing), the full list of now supported countries are listed here:


Lastly on fitness related things, they’ve added team based challenges to the wrist itself, which started back in June on the phone app:

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Finally, shifting to a few quick non-fitness things:

– There is an LTE version of the watch, using eSIM
– The Watch4 uses a 5nm processor for the first time in a Galaxy Watch
– The processor is 20% faster, and watch has 50% more RAM with a GPU that’s 10x faster than previous Samsung watches (as usual, with watch specs, we typically have to rely on manufacturers for this)
– The display is 450x450px
– There’s 16GB of storage space for music/apps/etc…
– Claimed battery life is 40 hours, which essentially means it’s daily charging like an Apple Watch
– 30 minutes of charging provides 10 hours of battery life (that’s actually surprisingly slow by watch charging standards)
– Spotify streaming can occur via LTE
– New Gesture controls, including simply shaking your wrist to dismiss a call
– Offering far more color strap options than previously

Finally, there’s an entirely new ‘One UI watch”, which is designed to use just the two buttons and touch screen. However, Samsung has retained aspects of the bezel controls on the base Galaxy Watch, which are familiar with Samsung users. While the Galaxy Watch4 Classic includes a full rotating bezel.

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Again, it’ll be interesting to see how this all works in real life once we get hands-on.



It’s widely considered that this is the last Hail Mary for Wear OS. Though, there’s arguably no better option than Samsung to try and pull this off. But one has to also wonder why Google didn’t go with Fitbit (which they acquired) for launching their first new Wear OS watch. Then again, perhaps Samsung simply said ‘Look, if you want us, we go first’ – and that was that.

Either way, I’m super interested to see what accuracy looks like on the Watch4, and to see if it pulls off what Samsung claims. If so – that’d be pretty significant, not just for watches, but electrical impedance body metrics in general, which have often left many wanting better results (both figuratively and literally).

The remainder of the watch seems similar to what we see across the board from watchmakers now – more incremental updates than massive shifts. As the wearables world continues to stabilize, there’s less reason for huge philosophical or technological changes.

With that – thanks for reading!


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  1. Greg Franks

    Blame Canada. No blood pressure or ECG.

  2. Jan Aniolek

    “The remainder of the watch seems similar to what we see across the board from watch makers now – more incremental updates than massive shifts.” – mostly agree, but it’s nice to see a 1.4″ screen in a 44mm package with 10mm thickness.

    1.4″ screen in Garmin terms is really big, this one (Watch4 44mm) promisess reasonability..

    I hope it’s not about how they meassure dimensions..

    • Corey

      Everyone knows that the correct way to measure a watch screen is to start the tape measure on the top left side of the screen, then wrap it around your arm twice, up and over the back of you neck, and back down to the bottom right side of the screen.

    • Jan Aniolek

      I am talking about the watch dimensions (44.4 x 43.3 x 9.8 mm [1.75 x 1.70 x 0.39 in] – according to gsmarena.com). How you measure the screen diameter is obvious – as you clarified to everybody..

  3. Someone

    Looks nice. Not sure I want to deal with shitty battery life though.

  4. Mike D

    Though I see it in the screen captures, no description here of how / how well the watch does blood pressure. This is something that other watches can’t seem to do, and I’m curious how Samsung pulled it off. Any insight?

  5. Convel

    Did they mention GNSS accuracy at all? For HRM-wearing fitness freaks, I think it’s a lot more important than how accurate the wrist-based sensor is.

    Also, there’s the question of how people can record activities in a way that allows automatic uploading to major platforms. They mentioned Strava access through the Google Play Store, but Strava’s current Wear OS app is extremely basic with very limited data fields and no support for external sensors. There are third-party apps like Ghostracer and Sporty Go!, but they’re nowhere near as polished as iSmoothRun for the Apple Watch. I hope Samsung has thought of this and has a good first-party solution.

    Wear OS qualms aside, $329.99 for the Watch4 44 mm LTE sounds pretty good. This is the only proper LTE watch that runs Google’s operating system and which doesn’t have an ancient chipset, after all. Early hands-on videos seem to show a fluid and responsive UI. Every other smartwatch manufacturer commited to the OS will likely have an even more difficult time until they can deliver Wear OS 3 on a Snapdragon Wear 5100 platform. Loyalty could also be spreading thin, but that’s an issue Samsung could be having as well among customers who recently bought a Tizen watch.

    • Frank Mills

      Yes, I found Strava, Google Fit and Sporty Go too basic on my Fossil for my running needs. If it won’t accurately show Current Pace and Distance and/or other user selected fields while I run, then automatically upload them to Strava, I’m out. I’ll wait until DCR does a full review.

  6. JD

    Typo Tipster —
    blood[y] oxygen
    process[or] is 20% faster
    relay on manufacturers
    looks like [for] the Watch4

  7. James

    I can’t overstate how much I hope Polar are all over this (WearOS3) and that they will release product in 2022.

    It sounds as though the next-gen chipsets are finally making some tangible improvements. They need to negotiate access to a chipset at least on par with this Watch4 and release e.g. a Vantage V3 using their specialist optical sensors and fitness apps which upload to Flow (they have already done this to a degree with the M600 of course).

    At a stroke it will properly solve music, maps and contactless payments sans phone (possibly even ant+ if anyone still cares 😉 ).

    • Convel

      Very good point on Polar having shown that they were willing to try Android Wear with their M600. The Casio GSW-H1000 and Suunto 7 also showcased that a brand can maintain its identity and services despite using a common operating system. What we certainly don’t need is more 28 nm A7 Wear 3100 and 12 nm A53 Wear 4100 wearables that can’t fully run Wear OS 3. Timing is crucial.

      Note that Snapdragon Wear 5100, which is likely to be the most popular SoC choice, is said to be on the Qualcomm ‘Bengal’ platform, meaning 11 nm Cortex-A73 or A53 cores. Slightly more dated than the 5 nm Cortex-A55 cores in Samsung’s Exynos W920.

      Polar wouldn’t have competition just from Samsung, Casio and Suunto in the Wear OS fitness space though. A Pixel watch, with Fitbit expertise baked in, is more likely than ever given Google has shown more confidence in both Wear OS and their hardware division of late. Then again, Polar isn’t small fry.

    • OM

      I’ve been in touch with a riding buddy who works for the Canadian distributor for Polar. I have the M600 and really like it (aside from the weight). I asked when the next wear OS is coming out – answer is not likely…

    • OM

      to be another Android Wear OS polar watch.

    • Tams

      I doubt Polar are going to risk getting burnt yet again so soon.

      And with the considerably worse battery life *Samsung* are getting with Wear OS 3 (which shows that really not much has changed), I can’t see a much smaller fish like Polar throwing away one of their main selling points (battery life) in order to get on board.

      What would they get? Fitness wise, they have pretty all they need done in-house. Smartwatch wise, they’d be competing with the likes of Samsung.

  8. gideon

    thanks for the post.
    hopefully there will be a way to pre set more than one countdown timer…a giant venu flaw

  9. Rui Pereira

    Some typos: “which focuses are areas like this” and “usually we have to relay on”

  10. Jon

    If you need to charge it every night, how is it going to measure your sleep?

    • Pavel Vishniakov

      You charge it before going to bed, as you do with Apple Watch. About a 30 minutes on a charger gives enough juice to go through the night and about 90-120 minutes recharge to 100%

  11. Jonathan Adams

    The important question for me is whether it will have full functionality without being logged in and sending my personal info to the Matrix A.I. AKA will it work sideloaded at least.

  12. Jonas

    Worth noting that ECG requires a Galaxy phone – according to samsung.com:

    “Meet the Samsung BioActive Sensor that measures ECG in real time. You can check and monitor abnormal heart rate and rhythm through ECG and send data straight to a compatible Galaxy phone to be easily shared. 3, 4”

    Where 4 is:

    “Requires Samsung Galaxy Smartphone with Android 7 or later, and Samsung Health Monitor app (available only at the Samsung Galaxy app store).”

    • Joop Verdoorn

      Certainly worth noting; apps like HRV camera (on Android) can give an accurate assessment of heart rhythm disorder (with a Poincare plot for instance) for free. The added value of a watch that still needs a smartphone for an ECG is therefore limited

    • Convel

      Despite the switch to Wear OS, it appears the pairing process on non-Samsung phones is still just as painful as when their watches were running Tizen. Also, they quietly dropped support for iOS. Yep, I still prefer Google’s take on Android and Wear OS over Samsung’s.

  13. Dennis

    Since My $400 Venu-2 does (inexplicably) NOT read it’s own Garmin ant+ or bluetooth powermeters.

    Will the galaxy watch4 read bluetooth POWER METERS???

    (i use Garmin Rally Spd pwr meter pedals)

    • No, zero chance. At least not with any native Samsung apps. Maybe with 3rd party apps, but we’ll have to see what (if any) Google Play store restrictions there are there for existing apps on these new devices.

      In any event, for your Garmin Venu 2, there’s this option: link to dcrainmaker.com

    • AdCo

      So, not a Garmin Killer / Replacement for triathlon.
      Sigh. I want 1 watch that does it all at some point!

  14. Toby

    So body composition…. Nice. Rather than de facto industry standard sending current up one leg and back the other and estimating based on your lower body, this one goes up one arm and back the other. So basically the question is whether you have fat legs or fat arms? Cool

  15. Rob Cordray

    Big Samsung fan here. It would be nice for the Body Composition stuff to be better than that of my Garmin Index S2. Note that this bar is as low as a bar can be!!

  16. Matt

    Do we know if the watch will be compatible with external heart rate monitors on the chest or upper arm like my polar verity sense?

  17. Flamarion

    Thanks for the post!
    Do you have any information about GPS accuracy?

  18. Han

    So the rotating bezel is the only difference between the two watches and will set you back an extra 100 dollar? Maybe I’m missing something, but why would you choose the classic model? Maybe just for 46mm model if you like a big watch?

  19. inSyt

    Is the display always on with 40 hour battery life?

    Interesting points:
    – 40 hour battery life. This should mean the watch should comfortably have enough battery life to measure sleep, even after the battery has degraded after a years usage.
    – 5nm processor. Finally the good stuff is making it’s way to smart watches, where it really is needed due to space limitations.
    – Snoring tracking + sleep blood oxygen levels combined. Neat way to use another device to improve sleep tracking. Take note other manufacturers.
    – Body composition measurement. Impressive accuracy. Take note other manufacturers.

  20. Oskars

    That battery life would stop me from purchasing this, even though it seems like a nice product.

  21. Pavel Vishniakov

    Considering body composition scales – I found my Withings Body+ to give exactly the same results as the device we have at gym (with multiple electrodes and stuff). Obviously the scales only give overall metric whereas gym device gives breakdown by body parts as well, but I wouldn’t call it a crapshot.

  22. Arild

    I get a feeling that the new Wear OS is close to 100% Google and the Samsung/Tizen part is the ported Samsung-Tizen apps and the promise of a larger user base. For now I will keep my Suunto 7 with it’s very good sports tracking features with maps and navigation, excellent tracking og sleep, heart rate and body resources, Google Pay, Spotify offline music coming any day now and very fast charging.

    • Arild

      Not to forget a battery life comparable to the GW4!

    • Tams

      I was hoping that it was the other way around, what with the UI being pretty much the one used with Tizen.

      But with user reports on real use battery life, it must be Wear OS under the hood. And it sounds like it really hasn’t got any better (scaling Android down like so was never going to be good), as even with a better, more power efficient SoC, Samsung are getting about half the battery life of their last Tizen based watch.

      It’s a shame that Google, with their crappy half-arsed OS and lack of eagerness to support it, have won out yet again.

  23. Kurt M Fainman

    did a word search…does this device work with a chest strap? thx

  24. BartMan

    Are you going to do full in-depth review for Galaxy Watch4?

  25. Matt

    I’m wondering the same thing.

  26. Martin Westerling

    I’m wondering one thing about the regular watch4. How will it work when wet and is the interface dependent on touch? I hope it will be possible to control workouts using only buttons. If not this is not useful for many workout scenarios. The same goes for when one is using gloves, ie. in the winter here in Sweden.

    The classic seems a bit bulky for my preferences even if the physical rotating bezel seems useful when wet or with gloves.

    • As someone who uses a touchscreen Venu sometimes for swimming, the touch screen when wet issue is just a very minor inconvenience, 90% of the time it works flawlessly.

    • gideon

      @martin westerling, I’m wondering the same. i have the venu and i can’t wait to find an alternative for this exact reason…also the no custom workouts and only one countdown timer 🙂

  27. Raul Trujillo

    I’d like to see it tested on actual workouts, running, day-to-day activities. Does the GPS take you to from point A to B and back to A? Does it measure the speed and distance properly? How does it compare with the Garmin and Fitbit sportswatches?

  28. Thanks Ray for the in-depth review. Cant wait to get my hand (and wrist) on one.

    Keep the good reviews coming

  29. Mick

    I cannot get past the poor battery life. My Huawei Watch GT lasts several days and its had constant use since launch. Its got no external app links and a pants HRM but I can live with that. I don’t want to be charging a watch once or even twice a day, what a faff.

  30. iacopo guagni

    hi, when will you do the galaxy watch 4 review?

  31. Svetozar Vesic

    Still no in depth review ? I understand there is lot of new stuf, but the Watch 4 isn’t so bad after all…

  32. Hoo boy where do I begin

    I REALLY wanted to like this watch. It allowed me to continue to use Samsung Health after they took all the sensors off phones. I like the recently added Google Voice integration. I liked the look and feel of the watch and the available apps. Since 99% of my fitness data is cycling or walking I didn’t thing any of the other sports watches were a good fit.

    Battery life: Abysmal. Some days I can get about 18 hours, but other days the watch will drain in 4-5 hours. No rhyme or reason for this — I wore the watch for the entire Triple Bypass Cycling event and was still at 50%, but another time I went to sleep at 85% only to have the watch shut down at 1% sometime in the night.

    Notification anomalies: Phantom Voice message notifications appear (LTE version) and cannot be dismissed on watch. Notifications from applications incomplete….some show full message, others just a “you have X new messages.”

    Support: Maddening. Sent the watch in for repair the first time and the unit was not checked for the issue stated in the repair order. At Samsung’s direction, I sent the watch in a SECOND time….I just received an E-mail for their repair center saying the watch is being returned unrepaired. No reason given and no one at Samsung seems to know what will happen next.

    Ray, if you’re reading this, I am now in the market for a sports watch. Is there an annual review of what’s out there?