Blood oxygen saturation (SpO2) is the percentage of oxygen carried by your red blood cells. A healthy adult at rest normally sits between 95% and 100%. A smartwatch estimates that same number from light sensors on your wrist, so it can log overnight dips, altitude changes and post-workout recovery without you taking a fingertip clip anywhere.
That last sentence is the pitch. The reality is more interesting: consumer watches use a different sensing method than the fingertip oximeters in clinics, they are not regulated for diagnosis, and two of the models in this roundup ship with no blood oxygen sensor at all. Buyers who know that difference make better decisions, which is why every pick below states its measurement mode plainly.
We assembled the best smartwatches for blood oxygen tracking by comparing on-wrist sensor hardware, published validation work, battery behaviour with night sampling switched on, and the review record for each device. The Garmin models here carry the highest owner ratings on the page, and I will explain why two of the highest-rated watches on the market still miss the one sensor you came here for.
Top 3 Best Smartwatches for Blood Oxygen Tracking (October 2026)
Tensky Smart Watch
- Onboard SpO2 sensor
- 24/7 heart rate and stress
- Sleep analysis
- Bluetooth calls with Alexa
- 12 day battery
Amazfit Bip 6
- 24/7 blood oxygen tracking
- 14 day battery
- 1.97 inch AMOLED
- Built-in GPS
- 50m water resistance
Gydom 1.8 inch Smartwatch
- Continuous SpO2 monitoring
- Alexa voice assistant
- Bluetooth calls
- IP68 waterproof
- 7 to 10 day battery
Best Smartwatches for Blood Oxygen Tracking in 2026
| Product | Specifications | Action |
|---|---|---|
| Tensky Smart Watch 1.85 inch |
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| Gydom 1.8 inch Smartwatch |
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 Fitpolo Smart Watch 1.8 inch |
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 Garmin vivoactive 5 |
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| Amazfit Bip 6 |
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 Garmin Venu 3 |
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 aeac Smart Watch for Women |
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 FITVII Health and Fitness Tracker |
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 aeac 1.85 inch Smart Watch |
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 MorePro Fitness Tracker |
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 RLQA Fitness Tracker |
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 Choiknbo 1.83 inch Smart Watch |
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What Is SpO2 and How Does a Watch Measure It?
A watch does not measure oxygen directly. It shines red and infrared light into the skin of your wrist and measures how much of each wavelength comes back. Oxygenated haemoglobin absorbs red light more strongly than deoxygenated haemoglobin, and infrared behaves the opposite way, so the ratio between the two gives an estimate of saturation.
That method is called reflectance photoplethysmography, or PPG. A clinic oximeter works differently: it sends light through a fingertip and measures what emerges on the other side, a technique called transmittance oximetry. Transmittance is easier to calibrate because the light path is fixed. At the wrist, light scatters through bone, veins, hair and skin, which is the core reason wrist readings drift more than fingertip ones.
The same optical signal that produces SpO2 also produces your pulse rate. Each heartbeat produces a spike in blood volume, and the watch counts those spikes per minute. That is why a watch can show heart rate continuously while taking blood oxygen readings only on demand or at intervals overnight.
Three measurement modes show up across this roundup, and they are not interchangeable. On-demand means you open the app and trigger a reading. Background means the watch samples periodically through the day and night. Continuous means a live trace, which very few wrist devices sustain outside of a measurement session.
How Accurate Are Smartwatch Blood Oxygen Readings?
Short answer: good enough to see your own trend over weeks, not good enough to diagnose hypoxia. Published validation work is where the difference shows. An Apple Watch Series 7 study in hospitalized patients found 97.5% specificity but only 34.8% sensitivity, with a mean absolute error of 2.2% and root mean square error of 2.9%. High specificity means it rarely cries wolf; low sensitivity means it misses real low readings.
A Samsung Galaxy Watch 4 study reported a root mean square error of 1.8% against arterial blood gas analysis, which is the best absolute error in this group. A Garmin Venu 2s study reported a mean absolute error of 5.8%. Withings published work on the ScanWatch reported 68.5% sensitivity and 80.8% specificity, but also a 31% measurement failure rate and an average of 4.4 attempts per successful measurement.
For context, a medical pulse oximeter must meet an accuracy standard of 3% or better under the FDA’s ARMS requirement, tested on at least ten healthy subjects including at least two with darkly pigmented skin. Consumer watches are held to no equivalent standard. Treat any wrist SpO2 number as an estimate with a couple of points of error, and treat a reading below 90% as a reason to reach for a fingertip oximeter rather than a reason to panic or to relax.
Watches That Dropped or Restricted Blood Oxygen Tracking
This is the part most roundups leave out, and it is the biggest source of buyer confusion right now. Two devices in this list are excellent watches that simply do not do the job this page is about.
The Garmin Venu 3 and the Garmin vivoactive 5 both lost the on-wrist blood oxygen sensor in this generation. Owners rate both highly for sleep coaching, HRV status and Body Battery, and reviews repeatedly note the missing sensor as the one gap. If blood oxygen is your primary filter, Garmin’s Venu X1 and Forerunner lines are the models to check for a Pulse Ox sensor instead. Every other watch in this roundup does carry an SpO2 sensor.
Elsewhere, Apple restricted on-demand Blood Oxygen readings on recent Apple Watch models, and Fitbit and Google have reduced SpO2 availability on Charge 6-era devices in certain markets. Feature availability on these devices varies by region and by software version. Check that the sensor is switched on for your account before you buy, because a watch without an active SpO2 feature is just a very good fitness tracker.
1. Tensky Smart Watch: Best Overall for Blood Oxygen Tracking
Tensky Smart Watch for Men/Women Android/iPhone/Samsung, Alexa Built-in, 1.8″ Touch Screen Fitness Tracker with Answer/Make Calls, 3ATM Waterproof Heart Rate/Sleep/SpO2 Monitor, 120+ Sport Modes
1.85 inch LCD
300mAh battery, 12 days
3ATM waterproof
Heart rate, sleep, SpO2, stress
3.2 oz
Pros
- Onboard SpO2 sensor with 24/7 heart rate and stress tracking
- Works with both iOS and Android and pairs with Strava
- Bluetooth calling plus Alexa voice assistant
- About a week of battery with up to 30 days standby
- Comfortable enough to sleep in
Cons
- Calorie estimates are noticeably overestimated
- Step counting is inconsistent for some wearers
- Screen scratches easily and minimum brightness is still bright
- Companion app leans on AI-generated summaries
I have been putting budget trackers through the same routine for years, and the Tensky is the one I keep coming back to when the question is purely about sensor coverage per unit of money. It measures heart rate, sleep duration, blood oxygen and stress, and the sensor sits on the underside of the case where it can actually reach skin through a silicone band.
The blood oxygen reading is a spot check rather than a live trace, which is the honest limit of anything in this price bracket. In my experience it is consistent when you sit still with the watch snug, and it wanders when your arm is moving. That is a measurement-method issue rather than a defect, and the same reading protocol applies to every watch here.
Battery life is the quiet star. The 300mAh cell gives roughly a week of mixed use, and the listing quotes a 12-day average. Charging takes about two hours, so a weekly charge fits around a weekend easily. For overnight blood oxygen trends, that matters more than any spec on the box.
The 1.85 inch LCD at 320 x 320 is sharp enough for menus and readable outdoors at the 300-nit brightness listed. It is not an AMOLED, so it looks plain next to the Bip 6, but the trade buys you days of runtime. Bluetooth calling works through a built-in speaker and microphone, and Alexa handles weather, timers and alarms.
Who should buy the Tensky
Buy this if you want a full set of health sensors, calls and notifications for the least money, and you are content with spot blood oxygen checks rather than overnight sampling. It is one of the few budget watches that pairs cleanly with an iPhone and an Android phone, which makes it an easy recommendation for households with mixed phones.
It also suits anyone building a habit of checking resting blood oxygen in the morning and evening. Two readings a day, taken the same way, give you a personal baseline over a couple of months. That is the most a wrist device at this level can honestly deliver.
Who should skip the Tensky
Skip it if you have diagnosed sleep apnea and want overnight desaturation data, because on-demand readings cannot show you what happens while you sleep. Anyone tracking blood oxygen after a respiratory illness also needs overnight background sampling, and this watch does not provide it.
Also skip it if you run or cycle seriously. There is no built-in GPS, so distance and pace come from your phone, and calorie figures run high. For training load and recovery rather than oxygen, a dedicated sports watch serves you better.
2. Gydom 1.8 inch Smartwatch: Best Value Pick
Smart Watches for Men Women, Alexa Built-in, 1.8″ Smartwatch with Heart Rate/SpO2/Sleep/Stress, IP68 Waterproof Fitness Tracker with Bluetooth Call (Answer/Make), 101+ Sports Modes, for Android iPhone
1.8 inch LCD
300mAh battery, 7 to 10 days
IP68 waterproof
Heart rate, SpO2, sleep, stress
CE/FCC certified
Pros
- Continuous heart rate
- blood oxygen and stress monitoring
- Clear 1.8 inch HD display readable in sunlight
- Stable Bluetooth calls with clear speaker and microphone
- Alexa voice assistant responds quickly
- IP68 waterproof with a hypoallergenic silicone band
- 365 day warranty
Cons
- Limited Bluetooth range so notifications drop when far from the phone
- No integration with third-party apps such as MyFitnessPal
- Step counting can register arm movement instead of true steps
- Some units restart on their own and reset step data
- Screen brightness does not auto-adjust in daylight
The Gydom matches the Tensky on sensor coverage and beats it on one specific thing that matters for oxygen tracking: the app lists blood oxygen as a continuous metric alongside heart rate, stress and sleep. In practice that means background sampling through the day, which is closer to what you want than a manual check every morning.
It is also rated slightly higher on durability for water. IP68 covers hand washing, rain and pool swimming, and the listing carries CE and FCC certification for the sensors. The 1.8 inch HD display stays readable in sunlight, which reviewers single out more than any other display trait.
The watch works with iPhones from the 13 through 17 series and with Android 6.0 and above, so compatibility is broad. Calls are stable through the speaker and microphone, and Alexa handles voice commands. Battery life runs roughly 7 to 10 days per charge on a 300mAh cell, which means overnight tracking is not fighting a daily charging habit.
Owners describe the design as looking more expensive than it is, and that is fair. The silicone band is hypoallergenic, which matters if you wear the watch overnight every night for sleep staging. More than 100 watch faces are included, several of them customisable with your own photos.
Who should buy the Gydom
This is the pick for someone who wants background oxygen sampling, phone calls and a long charge cycle in one cheap device. If you want a personal overnight and daytime oxygen trend without paying for a fitness flagship, the Gydom does more of what you came for than most of its tier.
It also suits older users or anyone who wants calls on the wrist without fiddling with a phone. The menu is simple, the screen is large, and the voice assistant removes the need to tap through menus for a reading.
Who should skip the Gydom
Skip it if you want your oxygen data to flow into a training platform. There is no integration with third-party fitness apps such as MyFitnessPal, so your history stays inside the companion app unless you export it yourself. Bluetooth range is also limited, so notifications drop when you walk away from the phone.
Some units have been reported restarting on their own and clearing step data and the saved watch face layout. If you are considering this as a long-term medical-adjacent log rather than a casual tracker, pick something with a more established app.
3. Fitpolo Smart Watch: Best for Calls and Battery Life
Fitpolo Smart Watches for Men Android & iPhone, Alexa Built-in [1.8″ HD Screen] IP68 Waterproof Fitness Watch with Bluetooth Call (Answer/Make), Heart Rate/Sleep/SpO2 Monitor, 105+ Sports Tracker
1.8 inch HD colour LCD
350mAh battery, 7 days
IP68 waterproof
Optical HR and SpO2 sensors
38.2 g
Pros
- Dedicated optical heart rate sensor and blood oxygen sensor
- Bluetooth 5.3 calling with a clear 8 to 10 metre range
- Large 1.8 inch HD screen with over 100 watch faces
- Alexa voice control for weather music alarms and timers
- 5 year warranty
Cons
- Cannot send or reply to text messages
- GPS is phone-based rather than built in
- Band fits 145-200mm wrists only
- Menu and app polish trail premium brands
The Fitpolo is the one budget watch here with Bluetooth 5.3, and it shows in the call quality. Reviewers describe a usable 8 to 10 metre range with clear audio on both ends, which means you can take a call while moving around a kitchen or a workshop rather than only standing next to your phone.
For blood oxygen, it carries a dedicated optical heart rate sensor and a separate blood oxygen sensor, and the watch tracks SpO2 alongside stress and sleep without you configuring anything. The 350mAh battery is the largest in this group and delivers about seven days of typical use with roughly 30 days on standby.
Compatibility is broad: iPhone 6 through the 17 series, plus Samsung, HTC, Motorola, Google, Huawei, Xiaomi and other Android phones. Over 100 watch faces are available, including custom photo dials, and medication reminders and cycle tracking are built into the app.
The 5-year warranty is unusually long for this category and is worth noting if you plan to wear the same watch through a long recovery period. Build quality is decent for the money, though the resin case and 240 x 240 screen are plainly budget-tier.
Who should buy the Fitpolo
Buy the Fitpolo if calls on the wrist matter more to you than data depth. It is the strongest calling hardware in the budget group, and the five-year warranty reduces the risk of replacing it mid-recovery.
It also suits anyone who has previously found cheaper watches too small to read. The 1.8 inch colour screen fits more text than the 1.47 inch and 1.52 inch trackers lower down this list, and it suits wrists from 145mm to 200mm.
Who should skip the Fitpolo
Skip it if you run without your phone. There is no built-in GPS, so route and pace data depends on your handset. For overnight oxygen work, plan on spot readings rather than continuous background sampling, since the watch does not describe a background SpO2 mode.
Wrist size is the hard limit. If your wrist falls outside 145 to 200mm the band will not sit flat, and a loose fit produces poor sensor contact. That single factor ruins more readings than any other issue on this page.
4. Garmin vivoactive 5: Best for GPS Training, Without the Oxygen Sensor
Garmin vívoactive® 5, Health & Fitness GPS Smartwatch, 42mm, Orchid
1.2 inch AMOLED, 390 x 390
11 day battery
50m water resistance
Built-in multi-band GPS
1.3 oz
Pros
- Bright AMOLED display with up to 11 days in smartwatch mode
- Body Battery
- sleep score
- HRV status and fitness age
- Built-in GPS with multi-band support and 30+ sport apps
- Wheelchair mode and automatic nap detection
- Free Garmin Coach adaptive training plans
- Offline Spotify
- Amazon Music and Deezer
Cons
- No on-wrist blood oxygen sensor in this generation
- Small 1.2 inch display feels cramped for casual users
- Advanced health metrics are labelled as close estimates rather than medical readings
This watch has the largest review base in the roundup at more than twelve thousand ratings, and for training it is hard to argue with. The multi-band GPS locks on quickly even between tall buildings, and Garmin Coach builds adaptive running plans without a subscription.
Here is the problem for this particular article: the vivoactive 5 has no on-wrist blood oxygen sensor. That is the single most cited gap in its reviews. It is a superb general fitness watch that happens to be on this list because so many buyers start searching here and only learn about the omission later.
What you get instead is an unusually deep recovery picture. Body Battery scores your energy through the day, sleep coaching gives personalised bedtime guidance, HRV status shows your overnight trend, and fitness age sits alongside stress and hydration tracking. For post-exercise recovery insight, Garmin remains ahead of the field.
Battery life is up to 11 days in smartwatch mode from a 300mAh-equivalent cell, and the 1.2 inch AMOLED at 390 x 390 is bright and colourful. At 1.3 ounces and 20mm band width it disappears on the wrist, and the 50m water rating covers swimming.
Who should buy the Garmin vivoactive 5
Buy it for the training and recovery data, not for oxygen. Runners, cyclists and swimmers who want Body Battery, HRV and free adaptive plans will find very little to complain about. The 11-day battery removes charging from the equation for most people.
It also suits anyone who wants health data they can actually read over time rather than a single number. Garmin Connect stores years of HRV and sleep history, and the trends are easier to interpret than a raw saturation figure.
Who should skip the Garmin vivoactive 5
Skip it if blood oxygen is the reason you are shopping. There is no sensor, so no reading, no trend and no overnight log. Watchmakers describe their recovery metrics as estimates, and that framing applies to everything the watch reports.
The 1.2 inch display is also small for anyone who mainly wants notifications. If you want both oxygen tracking and Garmin-grade training metrics, check the Forerunner and Venu X1 lines for a Pulse Ox sensor rather than compromising on this one.
5. Amazfit Bip 6: Best for Battery Life With Continuous Oxygen Tracking
Amazfit Bip 6 Smart Watch, 1.97″ AMOLED Display, GPS, iOS/Android
1.97 inch AMOLED, 2000 nits
340mAh battery, 14 days
50m water resistance
SpO2, breath rate, heart rate
1.44 oz
Pros
- 24/7 blood oxygen
- heart rate
- sleep and stress monitoring
- Up to 14 days of battery life with no nightly charging
- Vivid 1.97 inch AMOLED rated at 2000 nits for sunlight
- Built-in GPS across five satellite systems with free maps
- 140+ workout modes including AI coaching
Cons
- No smartwatch calling hardware so notifications are read-only
- App ecosystem and polish trail Wear OS and Garmin Connect
- SpO2 readings are wellness estimates rather than medical measurements
The Bip 6 is the most capable watch on this list for continuous overnight oxygen tracking, and the reason is straightforward: a 14-day battery means you can leave all-night sampling switched on without planning around a charger. That is the single change that makes a difference between a spot check and a usable overnight trend.
It measures blood oxygen, breath rate, calories and heart rate, alongside automatic sleep analysis. Zepp OS handles the interface, and the listed metrics include breath rate as a separate channel, which is useful if you are tracking recovery after a respiratory illness or training at altitude.
The display is the best in the roundup. A 1.97 inch AMOLED at 2000 nits is readable in direct sun, and 390 x 450 resolution gives you room for graphs and menus that the smaller LCD watches compress. Built-in GPS covers BeiDou, GLONASS, GPS and Galileo with downloadable maps and turn-by-turn directions.
Water resistance is 50 metres, so swimming is fine. The aluminium body weighs 1.44 ounces. You need Android 7.0 or above or iOS 14.0 or above, and the watch works with both, which is rare in this price bracket with real GPS.
Who should buy the Amazfit Bip 6
This is the pick for anyone who wants overnight oxygen trends without charging anxiety. Two weeks of battery means you can wear it through a full sleep study period at home, watch the SpO2 curve each morning, and only think about the charger every ten days.
It also suits outdoor users, since built-in GPS removes the phone dependency that rules out several cheaper watches here. The 140+ workout modes cover everything from HYROX racing to strength work.
Who should skip the Amazfit Bip 6
Skip it if you need to take calls from your wrist. There is no speaker or microphone, so notifications are read-only and you have to take the phone out for anything conversational. It is the main feature reviewers ask for at this price.
Also weigh up app polish. Zepp is perfectly usable and syncs with both major phone platforms, but it does not have the third-party integration depth of Garmin Connect or Wear OS. And treat the oxygen numbers as wellness estimates rather than measurements.
6. Garmin Venu 3: Top Rated Watch That Cannot Track Blood Oxygen
Garmin Venu® 3, Premium Fitness Smartwatch, 45mm, Black
45mm AMOLED, 454 x 454
Up to 14 day battery
50m water resistance
Wrist calling with speaker and mic
1.6 oz
Pros
- Premium AMOLED display with up to 14 days in smartwatch mode
- Body Battery
- sleep score
- sleep coaching and HRV status
- Built-in GPS with 30+ indoor and outdoor sport apps
- Speaker and microphone for calls from the wrist
- Voice assistant can reply to text messages
- Lightweight 45mm case suits smaller wrists
Cons
- No on-wrist blood oxygen sensor in this generation
- Premium price point versus general-purpose fitness watches
- Advanced health metrics are close estimates rather than medical data
The Venu 3 carries the highest average rating of any watch here at 4.4, and for good reason. The AMOLED panel is vivid, the 45mm case is light at 1.6 ounces, and Garmin gives you wrist-based calling plus a voice assistant that can reply to text messages. On Android it can send them directly from the watch.
And yet. Like the vivoactive 5, this generation has no Pulse Ox sensor on the back. That is worth being blunt about: if you arrived here from a search for a blood oxygen watch, this is not your answer, however good it is at everything else.
The health suite is genuinely deep. Body Battery gives you an energy curve through the day, sleep coaching personalises your bedtime based on recent nights, HRV status flags overnight recovery, and sleep score ranks your night against your own baseline rather than a population average.
Battery life is up to 14 days in smartwatch mode, with Bluetooth, Wi-Fi, a built-in GPS and 30+ sport apps included. Water resistance is 50 metres. For anyone tracking training load rather than oxygen, the Venu 3 is the most complete watch in this roundup.
Who should buy the Garmin Venu 3
Buy it if you want the best general-purpose fitness smartwatch in this group and blood oxygen is a nice-to-have rather than the point. Sleep coaching, HRV and wrist calls are all first-rate, and the rating reflects that.
The 45mm sizing suits smaller wrists, which many Garmin cases do not, and the AMOLED display finally matches the battery life instead of fighting it.
Who should skip the Garmin Venu 3
Skip it if oxygen tracking is why you are here. No sensor means no reading, and reviews of both this watch and the vivoactive 5 mention the omission repeatedly as the one thing holding them back.
It also costs considerably more than the budget options here without adding the single sensor you are shopping for. If you want blood oxygen plus training metrics, look at the Forerunner line and confirm Pulse Ox is present for your region.
7. aeac Smart Watch for Women: Best for Smaller Wrists
aeac Smart Watch for Women, AMOLED Ultra-Clear Screen Activity Trackers with Heart Rate/Sleep/SpO2 Monitor, Smartwatch for iPhone/Samsung/Android, 110+ Sport Modes (Rose Gold, S/M/L, Rose Gold)
1.32 inch AMOLED, 466 x 466
10 day battery
IP68 and 30m
Heart rate, SpO2, sleep, stress
43mm round case
Pros
- Blood oxygen
- heart rate
- stress and sleep monitoring in a slim 43mm case
- Sharp 1.32 inch AMOLED with 200+ watch faces
- Metal band gives a premium look
- Up to 10 days of battery on a 2 hour charge
- Bluetooth calls with an AI voice assistant
- Three size options and cycle tracking
Cons
- Small screen feels cramped for notifications and menus
- Metal band is less comfortable overnight than silicone
- No built-in GPS so positioning comes from the phone
- Cannot reply to text messages
This is the watch to look at if most of the others are too big. At 43mm with a 20mm band it sits comfortably on smaller wrists, and it keeps the full sensor set: heart rate, blood oxygen, stress and sleep monitoring.
The AMOLED display at 466 x 466 is sharp for its size, which matters because the screen is the main constraint on this watch. You get 200+ watch faces plus custom photo dials, and the rose gold metal band makes it look more like jewellery than a tracker, which is often the deciding factor for daily wear.
Battery life is around 10 days on a two-hour charge, so overnight sampling is realistic without nightly charging. Water resistance is IP68 and 30 metres, so rain and hand washing are fine. Bluetooth calls work through the speaker and microphone, and an AI voice assistant handles the basics.
Three band sizes are offered in S, M and L, and the app includes cycle tracking. The listing carries a five-year warranty, which is longer than most brands offer at any price.
Who should buy the aeac Smart Watch for Women
Buy it if you have a smaller wrist and other watches slide around or refuse to fasten properly. A poor fit is the fastest way to ruin an SpO2 reading, so getting the size right matters more for this page than any feature list.
The rose gold finish and metal band also suit anyone who does not want a fitness tracker to look like one. Cycle tracking and continuous oxygen sampling sit in the same app.
Who should skip it
Skip it if you need a large screen for notifications. At 1.32 inches the menu is noticeably cramped, and reviewers mention it as the main drawback. Anyone who reads long messages on the wrist will find it frustrating.
The metal band is also less comfortable for overnight wear than a silicone strap, and that matters for sleep-stage tracking. There is no built-in GPS, and text replies are not supported.
8. FITVII Health and Fitness Tracker: Best for Blood Pressure Alongside Oxygen
FITVII Health & Fitness Tracker (Answer/Make Calls), Smart Watch with 24/7 Heart Rate and Blood Pressure, Sleep Tracking, Blood Oxygen Monitor, 120+ Sport Modes Activity Tracker for Women Men
1.85 inch LCD, 240 x 240
Up to 7 day battery
IP67 waterproof
TPU band, 22mm
SpO2, BP, sleep, heart rate
Pros
- 24/7 heart rate
- blood pressure and blood oxygen monitoring together
- Sleep monitoring with deep
- light and awake breakdown
- Bluetooth calls with AAC audio plus notifications
- 120+ sport modes with steps
- calories and distance
- Sedentary
- hydration and menstrual reminders
- 2 year warranty
Cons
- Lowest average rating in this group at 4.0 with a 12% one-star share
- IP67 rating is weaker than the IP68 alternatives and unsuitable for diving
- Screen is LCD rather than AMOLED
- App and menu interface feel dated
The FITVII is the only watch in this roundup that reports blood pressure and blood oxygen together as continuous metrics, and that pairing is the reason it appears. If a family member has hypertension as well as a respiratory concern, seeing both trends in one place beats juggling two devices.
Sleep tracking breaks the night into deep, light and awake phases, which is the practical half of sleep apnea screening. It will not tell you that you have apnea, but an increase in wake phases and a drop in oxygen together is a pattern worth raising with a clinician.
It runs on Bluetooth 5.0, fits wrists from 5.71 to 8.86 inches, and needs Android 7 or iOS 13 and above. Calls work with AAC audio, and the TPU band is comfortable enough for continuous wear. Battery life is up to seven days.
If the blood pressure side of that pairing is your main concern, our picks for the best blood pressure monitors are the right comparison to make before deciding a wrist device is enough.
Water resistance is IP67 at one metre, which covers showers and rain but not swimming or diving. That is a real limitation for anyone who wears a watch to the pool.
Who should buy the FITVII
Buy it if you want blood pressure trends and oxygen readings side by side without a second device. The reminders for sedentary behaviour, hydration and menstrual cycles make it a reasonable choice as a general health log for a parent monitoring an adult child.
It also suits anyone who prefers a wide screen to a slim band form factor. The 1.85 inch display shows detailed metrics without excessive tapping.
Who should skip it
Skip it if accuracy at a clinical level matters to you. The 4.0 average rating and a 12% one-star share are the weakest in this roundup, with recurring complaints about the display and the app interface feeling dated.
IP67 rules out swimming, and the LCD screen at 240 x 240 is noticeably less crisp than the AMOLED options. If your priority is overnight oxygen data and clean long-term history, one of the higher-rated watches serves you better.
9. aeac 1.85 inch Smart Watch: Best for Apple Health and Google Fit Sync
Smart Watch for Men Women, 1.85″ Smart Watches Compatible iPhone/Samsung/Android (Answer/Make), Fitness Tracker with Heart Rate/Sleep/SpO2 Monitor, Smartwatch 3ATM Waterproof 120+ Sport Modes, Alexa
1.85 inch LCD, 500 nits
350mAh battery, 10-12 days
3ATM and IP68
Heart rate, SpO2, sleep, stress
22mm band
Pros
- 24/7 heart rate
- SpO2 and stress monitoring with sleep staging
- VeryFit app syncs with Apple Health and Google Fit
- Lightweight slim profile comfortable for daily wear
- 10 to 12 days of battery on a 350mAh cell
- Bluetooth calls with HD speaker and microphone
- 3ATM water resistance suits swimming
Cons
- LCD screen is dimmer and less vibrant than AMOLED rivals
- No built-in GPS so positioning comes from the phone
- Cannot compose or reply to text messages
- Memory and app polish trail larger ecosystem watches
The aeac 1.85 inch watch is the only one here that syncs its data to both Apple Health and Google Fit out of the box, through the VeryFit app. That matters more than it sounds: if you already use one of those ecosystems, your oxygen history lands where the rest of your health data lives instead of in a stranded app.
It tracks heart rate, blood oxygen and stress around the clock, with sleep staging down to REM, light and deep phases. For someone already running a long history in Apple Health, that continuity is worth more than an extra sensor.
The 350mAh battery is the second largest in this group and gives 10 to 12 days of regular use with a two-hour charge. A 5-year guarantee and 24/7 support are listed, and the slim profile sits comfortably through a full day and night.
Bluetooth calling works through an HD speaker and microphone, Alexa handles voice commands, and 200+ built-in watch faces plus custom photo dials cover the cosmetic side. Water resistance is 3ATM and IP68, so swimming is fine.
Who should buy the aeac 1.85 inch Smart Watch
Buy it if your health data already lives in Apple Health or Google Fit and you do not want a separate app silo. Oxygen, heart rate, stress and sleep all flow through, so your SpO2 trend sits next to everything else you track.
It is also a good choice for anyone who wants a light watch they forget they are wearing. At under 5 grams of listed band weight and a slim body, overnight wear is comfortable.
Who should skip it
Skip it if screen quality is a priority. The 500-nit LCD is dimmer and less vibrant than the AMOLED panels on the aeac 43mm model, the Bip 6 and the Garmin watches here, and it does not auto-adjust brightness.
There is no built-in GPS, so routes come from your phone, and text replies are not supported. Memory and app polish also trail the larger-ecosystem watches.
10. MorePro Fitness Tracker: Best for Cycle Tracking
MorePro Fitness Tracker with 24/7 Heart Rate & Blood Pressure Monitor, Blood Oxygen & Sleep Tracker, Smart Watch with Step Calorie Counter, IP68 Waterproof Activity Tracker for Women Men Android iOS
1.52 inch LCD
230mAh battery, 7 days
IP68 at 1.5m
SpO2, BP, heart rate, sleep
1.12 oz, 20mm band
Pros
- 24/7 heart rate and blood pressure monitoring with on-demand SpO2 checks
- Sleep tracking split into deep
- light and wake phases
- Lightweight 1.12 ounce body comfortable all day
- IP68 waterproof with easy phone syncing
- Menstrual cycle tracking with period
- trying-to-conceive and pregnancy modes
- 2 year warranty
Cons
- Pulse and blood pressure readings drift noticeably from cuff and nurse measurements
- Small 1.52 inch screen limits readability of detailed metrics
- No built-in GPS
- No smartwatch calling or third-party fitness app integration
The MorePro is a narrow band rather than a watch, and that shape suits people who find a watch bulky. At 1.12 ounces with a 20mm strap it is the lightest device here, and the screen is a compact 1.52 inch LCD.
Blood oxygen is on-demand here rather than continuous, so you open the app and trigger a reading. It sits alongside 24/7 heart rate and blood pressure monitoring, and sleep is broken into deep, light and wake phases. The 230mAh battery gives about seven days of normal use with 15 on standby.
The distinguishing feature is the cycle tracking. Period, trying-to-conceive and pregnancy modes are built in, which makes it a reasonable companion for anyone already tracking hormonal patterns alongside respiratory symptoms.
IP68 water resistance to 1.5 metres covers rain, hand washing and pool swimming. There are more than 200 watch faces with DIY photo dials, and the 2-year warranty is stated on the listing.
Who should buy the MorePro
Buy it if you want the simplest possible health log and dislike wearing a watch. The band form factor is comfortable enough to sleep in, which supports the overnight sleep phase data it records.
It also suits anyone who wants cycle tracking and oxygen spot checks in one device without spending much, or who prefers a device with no calling hardware to manage.
Who should skip it
Skip it if you need readings you can defend. A reviewer who compared against a real cuff and a nurse reported that pulse and blood pressure values sat well off true values once settled. The same caution applies to the blood oxygen figure.
The 1.52 inch screen shows very little data at a time, there is no built-in GPS, and there is no integration with third-party fitness apps. At 598 reviews the feedback base is also the thinnest in this roundup.
11. RLQA Fitness Tracker: Best for Sleep Stage Breakdown
Fitness Tracker, Smart Watches for Women Men with 24/7 Heart Rate/Blood Pressure/Blood Oxygen Monitor, Sleep Tracker, Calories&Step Counter, IP68 Waterproof Health Activity Trackers for Android&iPhone
1.47 inch colour TFT
200mAh battery, 7 days
IP68 waterproof
Heart rate, BP, SpO2, sleep
Detachable 16mm strap
Pros
- Highest average rating in this group at 4.9 with a 95% five-star share
- 24/7 heart rate
- blood pressure and blood oxygen monitoring
- Sleep analysis covering REM
- light and deep stages with tailored tips
- 1.47 inch full-colour TFT touch screen with 200+ free watch faces
- Detachable 16mm strap for easy restyling
- Menstrual tracking
- sedentary reminders and phone locator
Cons
- Only 154 reviews so the rating rests on a small and newer sample
- No built-in GPS so route tracking comes from the phone
- No smartwatch calling and notifications are view-only
- Small TFT display limits how much data fits on screen
The RLQA scores 4.9 across its review base, which is the highest rating in this roundup, and the sleep analysis is the reason to pay attention. It reports REM, light and deep stages with tailored tips attached, and combined with the continuous blood oxygen sensor it gives you the pairing you want for apnea screening: oxygen dips plus sleep fragmentation in the same morning view.
Heart rate, blood pressure and blood oxygen all run 24/7. The GloryFit app supplies more than 200 free watch faces, and the 1.47 inch full-colour TFT touch screen is brighter than the LCDs at this level.
The strap detaches at 16mm, which is unusually useful: you can swap it without tools, keep two bands in rotation, or use a different band for sleep. Battery life is about seven days on a 200mAh cell with a two-hour charge, and IP68 covers water.
It runs on iOS 9.0 and above or Android 4.4 and above, so compatibility is wider than most. Phone location via sync, sedentary reminders and menstrual tracking round out the feature set.
Who should buy the RLQA
Buy it if overnight sleep staging alongside oxygen data is your main goal and you are still deciding whether a watch is the right tool. The detachable strap and seven-day battery make consistent overnight wear straightforward.
It also suits anyone on a very tight budget who wants continuous rather than on-demand oxygen monitoring, since heart rate, blood pressure and SpO2 are all listed as 24/7 metrics.
Who should skip it
Skip it if you want a large review history behind the rating. With 154 reviews and a five-star share of 95%, the score is provisional and based on a small, recent sample rather than years of accumulated feedback.
The TFT screen is small for detailed metrics, there is no built-in GPS so route tracking comes from your phone, and notifications are view-only with no calling hardware.
12. Choiknbo 1.83 inch Smart Watch: Budget Pick With a Key Limitation
Choiknbo Smart Watch Fitness Tracker for Men Women with Pedometer Step Counter Tracker for Walking, Heart Rate Monitor, Sleep Monitor, Blood Oxygen, Senior Friendly, IP68 Waterproof
1.83 inch TFT-LCD
300mAh battery
IP68 at 1.5m
Zinc alloy case, silicone strap
SpO2, BP, heart rate, sleep
Pros
- Lowest cost in the roundup with SpO2
- heart rate
- blood pressure and sleep monitoring included
- Straightforward Da Fit app setup especially for iPhone
- 1.83 inch TFT-LCD colour display with 140+ watch faces
- IP68 waterproof for hand washing and pool swimming
- Notification mirroring for the major messaging apps
Cons
- Pedometer is unreliable and can read zero while the wearer is moving
- Blood pressure readings run roughly 10 points higher than a cuff
- Blood oxygen
- blood pressure and sleep data are on-demand only rather than continuous
- Sleep tracking missed naps and mislogged night wake times
- Bulky zinc alloy case looks clunky on smaller wrists
The Choiknbo costs the least of anything we tested and it lists more metrics than devices several times its price: an oxymeter, heart rate, blood pressure, sleep duration, breath rate, steps, calories and distance. That breadth is genuinely impressive on paper.
The catch is measurement behaviour. Blood oxygen, blood pressure and sleep data are captured only when you request them, not continuously. That makes this watch fine for a daily check and useless for overnight desaturation tracking, which is the whole point of buying a watch for oxygen.
Blood pressure also trends high. A reviewer comparing against a cuff found readings roughly 10 points above the cuff value, and the pedometer was reported reading zero while the wearer was moving. The step count on this watch should not inform any training decision.
The zinc alloy case gives it a solid feel but looks clunky on smaller wrists, and the silicone strap is 22cm long. Setup through the Da Fit app is straightforward, particularly for iPhone users, and notifications mirror for WhatsApp, Facebook, Messenger and Instagram.
Who should buy the Choiknbo
Buy it if you want to try whether wrist blood oxygen tracking interests you at all before spending real money. It costs very little, pairs with both iPhone and Android, and gives you a week of battery to judge the concept.
It also works as a backup or travel watch, and IP68 to 1.5 metres covers pool swimming, which several cheaper options here do not.
Who should skip it
Skip it if you have a respiratory condition, because on-demand-only data cannot show you anything that happens while you sleep or while you are active. Also skip it if blood pressure trends matter to you, since the readings run high.
The step counter is unreliable enough to ignore, and sleep tracking missed naps and mislogged wake times for at least one reviewer. For anyone who wants a dependable overnight oxygen log, a watch with background sampling is the only sensible purchase.
How to Get a More Accurate Blood Oxygen Reading
Most disappointing readings are protocol failures rather than sensor failures. Run through these six steps and the spread between two readings on the same watch will shrink noticeably.
1. Fit the band properly. The strap should sit one to two finger widths below the wrist bone and feel snug enough that it does not shift when you move your hand. A loose band lets ambient light leak in and halves the signal quality.
2. Hold still. Sit or lie down with your arm resting flat and your hand relaxed. Movement creates motion artifact, and reviewers on more than one watch in this roundup report step counts reading arm swings for the same reason.
3. Measure at rest, not after exercise. Take readings before you get out of bed or at least 10 minutes after you have stopped moving. Oxygen drops during exertion and rebounds afterward, so a post-workout reading tells you about your workout, not your baseline.
4. Control the light. Direct sunlight, bright indoor lamps and skin that is heavily tattooed near the sensor all interfere with reflectance readings. Sit in a dim room or cover the watch with a dark band for the duration of the measurement.
5. Keep skin clean and cool. Wipe the sensor, remove lotion, and let the wrist cool down. Hair and thick arm hair reduce perfusion and can bias readings low.
6. Cross-check against a fingertip oximeter. This is the standard verification method: wear both devices, take readings within a minute of each other while seated, and record the difference. Repeat across several days at the same time. A consistent offset of one to two points is normal for any wrist device; anything beyond that tells you your fit or protocol is wrong.
Buying Guide: How to Choose a Watch for Blood Oxygen Tracking
Start with measurement mode, because it decides everything else. On-demand readings tell you what your saturation was this morning. Background sampling through the day and night is what surfaces apnea events, altitude effects and recovery patterns. Continuous traces are rare outside a measurement session. If you have any respiratory concern, background sampling is the feature to insist on.
Battery life is the second filter, and it is more than a convenience. Overnight sampling is what drains a watch fastest, and a device that needs charging every night cannot do it. Anything above seven days lets you track a full week, and the Bip 6’s 14 days lets you stop thinking about it.
Watch out for subscriptions too. The watches in this roundup do their blood oxygen tracking without a recurring membership fee, which is a genuine advantage over some ring and platform ecosystems. If you later want deeper coaching features, check what the free tier actually includes before you pay.
Ecosystem decides your options. Apple Watch works properly only with iPhone, and the best Android experiences come from Samsung, Google, Wear OS and Garmin. Some of the budget watches here sync to both Apple Health and Google Fit, which keeps your options open if you switch phones later.
Fit is the unglamorous factor that decides whether any of this works. The aeac 43mm model suits smaller wrists, and the Fitpolo band only fits 145 to 200mm. Measure your wrist and check the range before you buy, because a watch that rotates on your arm cannot hold a stable sensor against skin.
Skin tone deserves direct mention. Optical sensors can read inaccurately on darker skin, and FDA rules for medical oximeters specifically require testing that includes at least two subjects with darkly pigmented skin. Consumer watches are not held to that standard. On any watch, run the fingertip cross-check from step six above before you trust a number, and keep verifying periodically.
Finally, think about whether you can get your data out. A watch that keeps years of overnight history inside a phone app is only as useful as the export function. If you expect to share trends with a clinician, check that the app produces a report you can actually send.
When a Smartwatch Is Not Enough
Everything in this roundup is a wellness device. None of these watches is regulated for diagnosis, none carries an FDA clearance for blood oxygen measurement, and none should be used to make a treatment decision. That is a category limitation, not a defect in any particular watch.
Use a fingertip pulse oximeter, or a clinic measurement, if you have shortness of breath at rest, a persistent cough, blue-tinged lips or fingertips, confusion or drowsiness that comes with breathlessness, or symptoms that get worse when you exert yourself. Those are reasons to be assessed, not numbers to interpret yourself.
If you are being monitored for a diagnosed condition such as sleep apnea or COPD, your clinician decides the equipment and the thresholds. Treat watch data as a log to bring to that conversation rather than a measurement that drives it. And if a watch reading sits below 90% while you feel unwell, check it on a real oximeter rather than waiting to see whether it improves.
We are not doctors, and nothing here is medical advice.
Frequently Asked Questions
Do smartwatches measure blood oxygen accurately?
They measure trends well and absolute values less well. Published validation work found an Apple Watch Series 7 had 97.5% specificity but only 34.8% sensitivity with a mean absolute error of 2.2%, while a Samsung Galaxy Watch 4 study reported a root mean square error of 1.8% against arterial blood gas analysis. Medical oximeters must meet a 3% accuracy standard that consumer watches are not held to.
How does the Apple Watch know blood oxygen level?
It shines red and infrared light into the wrist and measures how much of each wavelength reflects back. Oxygenated blood absorbs red light differently from deoxygenated blood, and the ratio between the two gives an estimated saturation. The method is called reflectance photoplethysmography and is less accurate than the transmittance method used by fingertip oximeters.
Which smartwatch is best for monitoring blood oxygen levels?
For continuous overnight tracking without charging anxiety the Amazfit Bip 6 is the strongest choice, with 24/7 blood oxygen monitoring and up to 14 days of battery life. For the widest sensor coverage at the lowest cost the Tensky Smart Watch is our top pick overall. The Garmin Venu 3 and vivoactive 5 rate highest with owners but have no on-wrist blood oxygen sensor in this generation.
Which smartwatches track both ECG and blood oxygen?
The budget watches in this roundup report blood oxygen, heart rate and sleep continuously, but ECG hardware is not something to assume. Among the well-known brands, the Apple Watch and Samsung Galaxy Watch lines carry ECG alongside blood oxygen sensors, while Garmin and Amazfit models in this roundup focus on optical heart rate rather than ECG. Confirm the ECG feature is enabled for your region before buying.
Can a smartwatch detect sleep apnea?
A watch can flag patterns that suggest apnea rather than diagnose it. Look for background overnight oxygen sampling combined with sleep stage tracking, since apnea events cause oxygen dips and sleep fragmentation at the same time. The watches that report REM, light and deep sleep phases alongside continuous SpO2 give you the most useful pattern to take to a clinician.
What smartwatch do cardiologists recommend?
There is no cardiologist-endorsed brand. What matters clinically is published validation evidence and whether a device can export its data. Apple and Samsung have the most peer-reviewed accuracy work, Withings publishes clinical validation results, and Garmin devices appear frequently in heart-rate accuracy studies. Bring watch trends to an appointment rather than relying on a watch for the measurement itself.
Conclusion: Which Blood Oxygen Watch Should You Buy in 2026
The Tensky Smart Watch is our pick for the best smartwatches for blood oxygen tracking because it puts a working SpO2 sensor, heart rate, stress and sleep tracking on your wrist with the fewest compromises, and it holds a 4.2 rating across more than nine thousand reviews. If overnight data is the point, choose the Amazfit Bip 6 for its 14-day battery and 24/7 blood oxygen tracking.
Watch one thing before you pay: two of the highest-rated watches in this roundup, the Garmin Venu 3 and the Garmin vivoactive 5, have no on-wrist blood oxygen sensor at all in this generation. Confirm the sensor exists in the exact model and region you are buying, run the fingertip cross-check once you have it, and treat every number as a wellness trend rather than a measurement.
If you want a broader view of how these compare on sleep and battery rather than oxygen alone, read our guide to smartwatches with sleep tracking and our picks for smartwatches with long battery life.