Free tools Windows power users keep installed
One-click scans. No signup required.
Fitbit’s Estimated Oxygen Variation (EOV) graph is no longer available: Google removed it when the Fitbit app became the Google Health app on May 19, 2026. The current replacement is overnight SpO₂ data, found in Google Health under Health > Blood Oxygen.
Neither the former EOV graph nor current wearable SpO₂ readings can diagnose or rule out sleep apnea. They can offer general wellness context, but symptoms or persistent concerns should be discussed with a healthcare professional.
What happened to Fitbit Estimated Oxygen Variation?
The former EOV graph showed estimated fluctuations in blood-oxygen saturation during sleep, not a precise oxygen percentage at each moment. Smaller variations indicated relatively consistent estimated levels; larger variations could be associated with breathing disturbances, but did not establish their cause.
Google says EOV is no longer available in Google Health. Its documented replacement is nightly SpO₂ data. There is no verified setting or supported navigation path to restore the old EOV graph, so instructions that say to find an “Estimated oxygen variation” card under Sleep refer to the discontinued Fitbit-app experience.
#1 Best Overall
- 【All-day Activity Tracker】: ENGERWALL IP68 Waterproof fitness tracker can record and track your daily steps, calories burned, exercise distance and time. It can also monitor your Body Temp, Heart Rate, Blood Oxygen and Blood Pressure. IP68 waterproof ensures that you don't need to take it off for daily hand washing and swimming, but don't soak it in water for a long time or wear it for hot baths, saunas.
- 【Slim and simple band design】The design concept of this tracker’s band is slim and unique, offering a comfortable and lightweight wearing experience. Suitable for men, women and the elderly.
- 【Heart Rate Monitor and Sleep Tracker】: Smart tracker can detect heart rate, blood pressure, blood oxygen, and body temperature in daily life. Monitor your sleep and analyze your sleep quality through Fall Sleep, Deep Sleep, Light Sleep, REM Sleep. You can view daily, weekly, and monthly data in the APP "Runmefit" to help you better understand your health status and lead a healthy lifestyle. [IMPORTANT] The blood pressure measurement feature must be downloaded and enabled within the app.
- 【Call and message notifications】: You can receive text messages and SNS notifications (including Facebook, Twitter, WhatsApp and Instagram) directly on your wrist. When your phone's Bluetooth is turned on, if you receive a message, the watch will vibrate to remind you and you can view the specific message. This function is very practical whether in work or life.
- 【Working Time】: Smart Fitness Watch is the best partner at work, you can set it on the mobile APP ‘Runmefit’: up to 5 sets of alarms, you don’t have to worry about being late for appointments or forgetting important things. You can set drinking Water Reminders and Sedentary Reminders to establish a healthy way of working.
How to find overnight SpO₂ in Google Health
- Open the Google Health app, formerly the Fitbit app.
- Tap the Health tab.
- Tap Blood Oxygen.
- Wear your device for a full day, including overnight, and sync it in the morning before checking your data.
Google’s transition to Google Health began on May 19, 2026. Fitbit users also need to move to a Google Account to continue using the service. See Google Health’s redesign information and Google’s setup requirements.
SpO₂ and EOV: what they meant
SpO₂ is an estimate of the percentage of blood carrying oxygen. Fitbit devices estimate it during sleep using red and infrared optical sensors on the back of the device, which analyze light reflected from the skin and blood vessels. It is not a clinical arterial blood-gas measurement, and Google describes the feature as general wellness information, not medical use.
| Metric | What it represented |
|---|---|
| SpO₂ | Estimated average blood-oxygen saturation and the range detected during sleep. |
| Estimated Oxygen Variation | Estimated changes or fluctuations in blood-oxygen saturation during the night. This former graph is discontinued. |
Google says sleep SpO₂ values are often lower than daytime values because breathing is typically slower during sleep, and that sleep readings are generally above 90%. This is a broad description, not a diagnostic threshold for an individual. For details, see Google’s guide to tracking blood oxygen saturation.
Rank #2
- Fitbit Charge 6 tracks key metrics from calories and Active Zone Minutes to Daily Readiness and sleep; move more with 40+ exercise modes, built-in GPS, all-day activity tracking, 24/7 heart rate, automatic exercising tracking, and more[1]
- See your heart rate in real time: Just link your Charge 6 to compatible exercise machines, like treadmills, ellipticals, and more[2]; and stay connected with YouTube Music controls[3]
- Tune into your body: Track your response to stress with a stress management score; learn about the quality of your sleep with a personalized nightly Sleep Score; and wake up more naturally with the Smart Wake alarm
- Run your routine with Google essentials: Find your way seamlessly during runs or rides with turn-by-turn directions from Google Maps on Fitbit Charge 6; and when you need a snack break on the go, just tap to pay with Google Wallet[1,4]
- Unlock more with Google Health Premium: With a premium membership, get personalized coaching that’s built with Gemini and adapts to your life[7]; get a 3-month trial at no cost to you[5] (Google Health Premium subscription sold separately)
Which devices support SpO₂?
Google’s current instructions list these devices and setup requirements. Availability may vary by region.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errors| Device | Requirement for SpO₂ tracking |
|---|---|
| Versa, Versa Lite Edition, Versa 2 | Use an SpO₂ clock face. |
| Inspire 3, Sense series, Versa 3, Versa 4 | Install an SpO₂ clock face or the SpO₂ app. |
| Charge 4, Charge 5, Charge 6, Luxe | Install the SpO₂ app. |
| Google Pixel Watch series | SpO₂ tracking is included automatically; no clock face or app is required. |
Install an SpO₂ clock face
- Open Google Health and tap Connections.
- Select your device, then tap Watch faces.
- Tap the Clocks tab and search for “SpO2.”
- Select a clock face, tap Install, and grant the requested permissions.
This clock-face setup applies to Inspire 3, Sense-series, and Versa-series devices, as listed in Google’s SpO₂ instructions.
Install the SpO₂ app
- Open Google Health and tap Connections.
- Select your device, tap Watch faces, and search for “SpO2.”
- Select SpO2 or SpO2 Tracker, then tap Install.
The app runs in the background and may not appear as a normal app icon on the watch. Google lists support for Charge 4, Charge 5, Charge 6, Inspire 3, Luxe, Sense-series, Versa 3, and Versa 4.
Rank #3
- Google Fitbit Air is the unbelievably comfortable, exceptionally smart way to transform your health[1]; and Google Health brings together effortless tracking and adaptive coaching to help make the most of your everyday[2]
- Unlock more with Google Health Premium: With a premium membership, get personalized coaching that’s built with Gemini and adapts to your life[2]; get a 3-month trial at no cost to you[5] (Google Health Premium subscription sold separately)
- Comfortable fit - One Size Tracker (130-210 mm): The lightweight, micro-adjustable fit sits comfortably and quietly, so you can wear Google Fitbit Air through work, play, and sleep; advanced sensors and new algorithms power more accurate, precise health tracking, 24/7[1]
- Designed for every occasion: With no screen to distract you or disrupt your style, your tracker moves seamlessly from bracelet to workout band to sleep band, and you can change looks in seconds – just press the pebble in, click, and go
- Long battery life: Google Fitbit Air’s battery lasts up to a week, and fast charging gets you one day of battery life in just five minutes[6,7]
Why SpO₂ data may be missing
Missing data or dashed lines do not by themselves indicate a health change. Google documents several collection and display issues to check:
- Less than three hours of quality sleep, or too much movement during sleep.
- Low battery or a device that did not record the complete sleep session.
- The device has not been synced in the morning, or the reading is still processing; it can take about an hour after waking or syncing.
- SpO₂ was just enabled. The device does not measure retroactively, so data may begin with the next sleep session.
- Permissions for the SpO₂ clock face or app are disabled.
- Poor fit or position. The device should touch the skin, sit slightly higher on the wrist, and be snug without constricting.
- Tattoos or limited circulation may affect the optical sensors.
- SpO₂ tracking is not available in your region.
If data is still absent, check these conditions against Google’s troubleshooting guidance.
Does oxygen variation indicate sleep apnea?
Sleep apnea is a disorder in which breathing repeatedly stops and starts during sleep. It can reduce oxygen levels and fragment sleep. Possible symptoms include loud snoring, gasping, witnessed breathing pauses, daytime sleepiness, dry mouth, morning headaches, and frequent nighttime urination. See the NHLBI list of sleep-apnea symptoms.
Rank #4
- 【All-day Health Monitor】The fitness tracker watch will automatically track your real-time heart rate, blood pressure and blood oxygen throughout the day to help you better understand your health. Equipped with a high-performance chipset, the fitness tracker automatically analyzes your overall sleep quality (deep/light/wake time) at night and gives you a nightly sleep score in the app to help you adjust your lifestyle and make you healthier.
- 【Smart Notification Remider】 With Bluetooth connection to your phone, it can support incoming calls/text alerts/APP message notifications (WhatsApp/Facebook/Instagram etc.), you will never miss your important messages. With the fitness watch, you can also perform sedentary reminder, water reminder, alarm clock, stopwatch, remote control photo, find devices, etc. to make your life healthier and smarter.
- 【25 Sports Modes】 Fitness tracker supports 25 professional sports modes, you can choose any number of sports modes as your exclusive sports modes in the app, such as walking, running, dancing, yoga, etc. and track your steps, heart rate, distance and calories to help you stay motivated, accomplish your sports goals, record your sports data, and make your sports more scientific.
- 【Long Battery Life】The fitness watch uses magnetic fast charging to provide a better battery life experience. It takes 1-2 hours to fully charge and can be used for up to 7 days of regular use and 15 days of standby. Compatible mobile phone system: android5.0 (inclusive) and IOS9.0 (inclusive) or above.
- 【1.1" AMOLED Touch Color Screen】AMOLED HD touch color screen is designed with clear and bright display, providing you with high quality touch and visual experience. This smartwatch includes a large number of original dials and supports custom dials.
Repeated overnight oxygen fluctuations can be consistent with breathing disturbances, but an EOV or SpO₂ pattern alone cannot establish that a person has sleep apnea. The American Academy of Sleep Medicine says consumer sleep apps and devices cannot diagnose sleep apnea or confirm that it is absent. Diagnosis requires evaluation by a medical professional and, when appropriate, a sleep study or medically supervised home sleep-apnea test. Learn more from the AASM advisory and NHLBI diagnosis guidance.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.How to use wearable oxygen readings responsibly
- Do not treat a high former EOV pattern or a single SpO₂ reading as proof of sleep apnea.
- Do not treat a normal-looking reading as proof that sleep apnea is absent.
- Remember that movement, fit, circulation, tattoos, and other factors can affect wearable readings.
- If you have symptoms or persistent concerns, discuss them with a healthcare professional rather than relying on the graph or attempting to diagnose yourself.
The FDA notes that pulse-oximeter readings have limitations and can be affected by circulation, skin pigmentation, skin temperature, skin thickness, tobacco use, and nail polish. A low wearable reading is not automatically an emergency; persistent low readings or concerning symptoms should be discussed with a healthcare professional. See the FDA’s pulse oximeter information.
FAQ
Can I still view Fitbit Estimated Oxygen Variation?
No. Google says the former EOV graph is no longer available in Google Health, and there is no verified supported setting or path to restore it.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Repair Windows errors before they cause bigger problemsFix Now →Best Value
- Inspire 3 is the tracker that helps you find your energy, do what you love and feel your best – all you have to do is wear it;
- Compatible with Apple iOS 16.4 or higher and Android OS 11.0 or higher
- Move more: Stay motivated with a Daily Readiness Score, Active Zone Minutes, all-day activity tracking and 24/7 heart rate, 40+ exercise modes, automatic exercise tracking, and reminders to move
- Stress less: Keep an eye on your well-being with a daily Stress Management Score, mindfulness sessions, relax breathing sessions, irregular heart rhythm notifications, SpO2, menstrual health tracking, resting heart rate, and more[1,2]
- Sleep better: Automatic sleep tracking, a daily detailed Sleep Score, smart wake vibrating alarm, and sleep mode help you improve your sleep quality[3]
Where can I see my Fitbit oxygen data now?
Open Google Health, tap Health, then tap Blood Oxygen. Wear your device overnight and sync it in the morning.
Does a high oxygen variation or low SpO₂ reading mean I have sleep apnea?
No. These consumer-device readings cannot diagnose sleep apnea. A medical professional can assess symptoms and decide whether a sleep study or supervised home test is appropriate.
Can a normal SpO₂ reading rule out sleep apnea?
No. A normal-looking wearable reading does not confirm the absence of sleep apnea. Consumer devices can miss events or produce unusable data; seek professional evaluation if you have symptoms or concerns.
Why is my Blood Oxygen data missing?
Check sleep duration and movement, battery, morning syncing and processing time, app permissions, device fit, and regional availability. Newly enabled tracking starts with a later sleep session rather than filling in past data.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
