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We tested products from Nonin, Innovo, Masimo, Oxiline, and others to find the best pulse oximeters on the market
Credit: Clark Tate
By Clark Tate ⋅ Senior Review Editor ⋅ Mar 14, 2024
To help you find the best pulse oximeter, we researched dozens before buying the top 15 to test side-by-side. Sifting through the options can feel overwhelming, especially since prices vary widely. We tested these pulse oximeters on both dark and light skin tones and under hypoxic conditions with the help of a professional freediver to gauge their consistency, comfort, and durability. We also dove into research studies to support our results. Keep reading to find the right model for your needs and budget.
Editor's Note: Our pulse oximeter review was updated on March 14, 2024, to include information on how we tested these products and to offer up some extra recommendations in our award section.
The Nonin Onyx Vantage 9590 is the only medical-grade pulse oximeter we tested, and you may need a prescription to buy it. Research has shown that it's highly accurate. A study in the European Respiratory Journal compared Nonin readings to arterial blood gas (SpO2) readings (the gold standard in blood oxygenation testing) and the results correlated well. Because of this study, we used the Onyx Vantage as a benchmark in our accuracy testing. It performed consistently and provided the most rapid results, with an average response time of just over three seconds. It is also the only device that claims to work well with all skin tones, for patients with poor circulation, and even those wearing fingernail polish.
Studies show that pulse oximeters can dangerously overestimate oxygen levels in a percentage of very sick patients, and they are more likely to do so with dark-skinned patients. Nonin claims they have solved this issue, citing a study showing that the Onyx Vantage only significantly overestimates oxygen levels when they fall below 70%. Since normal oxygen saturation is 95% or above, it's better at catching early SpO2 dips than the other two devices tested. We didn't notice a difference in the readings between our dark-skinned and light-skinned testers, though they were healthy with normal blood flow and oxygen levels. Pulse oximeters tend to work well under those conditions. The only downsides we uncovered are that this device is expensive, doesn't pair with an app to record any of your data, and may require a prescription. But if you want a medical-grade device, ask your doctor about this one. If you merely want a device for spot monitoring, the Innovo Deluxe iP900AP is a great pick that delivers pretty accurate results at a fraction of the cost.
Most of these pulse oximeters are over-the-counter models not intended for medical use.
Prescription pulse oximeters must undergo clinical accuracy testing and FDA review. They are used by doctors, in hospitals, and by anyone with a prescription from their doctor. All but one of the devices we review here are "general wellness products" for sports, aviation, or altitude use and are not required to achieve FDA approval. The Nonin 9590 is the exception. It's best to get a prescription from your doctor to purchase it directly from the company, though some commercial distributors don't require one.
The only medical-grade option in the review, the Nonin is also incredibly easy to use.
The Innovo Deluxe iP900AP monitor is a comfortable and reliable option that performed quite well in our tests. We appreciate how easy it is to use. Just insert the included batteries, and it quickly reads your SpO2, pulse rate, and perfusion index (PI). At the same time, it gives you plenty of customizable options. You can set up high and low SpO2 or pulse rate alarms, turn on a (really annoying) alert beep, adjust the display brightness, and rotate the display readout to face you or a care nurse — all by manipulating its one power button. (Just keep those instructions handy.)
The display is also useful in figuring out how reliable the readings are. If the perfusion index is below 0.3%, you might not have enough blood in your hands to get accurate results. In this case, you can warm them up with a cup of tea, a short walk, or other light movements. Similarly, the pulse rate bar should be above 30%, and the plethysmograph waveform (which measures your blood flow) should show consistent wave heights before you trust a reading. This device feels exceptionally sturdy, and we appreciate that it helps you get an accurate reading. If you don't require an app to record your readings, the Innovo Deluxe is a good option to consider. If you're keen on an app, we liked the one associated with the Oxiline Pulse XS Pro, but that monitor isn't the most accurate or comfortable from our testing.
The Innovo is easy to operate and provides handy extras like a perfusion index to make sure you're getting a good reading and an optional low oxygen alarm.
The Masimo MightySat delivers a wealth of health information quickly and consistently. It tracks more data than any other device in our test, including blood oxygen saturation (SpO2), pulse rate, respirations per minute, perfusion index (PI), and pleth variability index (PVi), which can help you or your doctor manage your fluid intake. Its SpO2 and pulse rate measurements are comparable to the other devices we tested. And it will keep track of your stats if you download the Masimo Personal Health App. What we really love about this option is its comfort. Its clever double hinge and wide shape distribute pressure evenly across a padded cradle. You can also change the display's orientation for easy reading. Like Nonin, Masimo claims that its devices work accurately with darker skin tones.
Based on the price, we expected a lot from this device. You get more data with the MightySat, but despite the impressive data collection, it is not rated as a medical device. It didn't seem to register oxygen readings below 90%. According to NYC Health, you should call your doctor if your levels fall below 95%. Levels at or below 90% are a 911 emergency. We liked the iPhone version of the app, but the Android version is harder to use. Our main gripe, though, is the price point. Still, the MightySat may be the one for you if you want an extremely comfortable device for quick check-ins on important health metrics. If you don't need an app or quite so much data, the Innovo Deluxe iP900AP will save you a good chunk of change.
The Masimo MightySat provides more information than any other device tested.
The Wellue SleepU Wrist is powered by Viatom and is meant to monitor oxygen saturation levels continuously while you sleep. It snaps on like a watch with a small, flexible, and comfortable finger loop, keeping any weight off your finger. The ViHealth app captures and charts your data anytime you leave it on for over two minutes. The app is not the easiest to use, but it doesn't take long to master and provides plenty of information. The ring will vibrate if your SpO2 levels drop or if your pulse rate rises or falls past predetermined thresholds. During breath-hold testing, the SleepU vibrated every time our freediver tester experienced hypoxic contractions. A USB cable recharges the device.
The SleepU provided accurate and consistent readings for all our testers. However, registering the first reading for our Black testers took twice as long as it did for our white testers. The device is designed to monitor oxygen levels over a longer period, so the extra 10 seconds doesn't seem like a big issue, but it's still something worth noting. It is also more delicate, comes with many small pieces, and is more challenging to put on than many other units we reviewed. Moreover, the finger loop is one-size-fits-all, which may not work for everyone. Finally, this pulse oximeter is expensive. Still, the SleepU might be the right fit for monitoring your oxygen levels while getting a good night's rest. If you are shopping for a model suitable for a child that's lighter on your wallet, the Zacurate Children Digital features a smaller finger port. The Innovo Deluxe iP900AP is also a great budget buy if you're shopping for yourself.
We didn't immediately notice the cartoon polar bear on the face of the Zacurate Children Digital, but we must admit, it's pretty cute. Designed for quick check-ins for children 2-12 years old, the cuteness is intentional. Aside from the kid-friendly facade and very small finger port, this non-medical device operates just like the others in the test. Simply press the polar bear's nose (we love this), let him eat your finger, and you'll have a SpO2 and pulse rate reading in about seven seconds.
The device has a waveform to help gauge the consistency of your kiddo's blood flow and thus how accurate a reading might be. Since it's designed for child-size fingers, the Zacurate is petit, and we often struggled to get it to register our adult hands, even when using our pinkies. When it did, however, its readings were consistent and in line with the most accurate devices we tested. If you need a pulse oximeter for monitoring your child's oxygen stats, we recommend the Zacurate. For everyone else looking to monitor their own, the Nonin Onyx Vantage 9590 was the top competitor in our accuracy test and our overall favorite.
While a bit small for our fingers (even the pinkies) this children's monitor from Zacurate performed well in our consistency and accuracy tests.
Credit: Clark Tate
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Overall, we were impressed by the reliability of these pulse oximeters.
Credit: Clark Tate
How We Test Pulse Oximeters
After reams of research, we rounded up a group of the most popular pulse oximeters on the market to test extensively, purchasing each one at full price. Our team checked their oxygen saturation during multiple rounds of testing while at rest, taking averages and timing how long each display took to get its first reading. We tested them during dry, static apnea training for freediving, with breath holds lasting up to 3 minutes and 45 seconds and oxygen levels dropping to 80%. Then we tested each device against the Nonin Onyx Vantage 9590, which offers research-backed accuracy levels. Afterward, we assessed their consistency, took notes on ease of use, and compared their comfort and features. We break our testing down into five comprehensive performance metrics:
Accuracy and Consistency (30% of overall score weighting)
Ease of Use (25% weighting)
Features and Versatility (15% weighting)
Comfort (15% weighting)
Quality (15% weighting)
Why You Should Trust Us
This review is headed up by Clark Tate, an outdoor athlete who loves data. Clark holds a Wilderness First Responder certification and has a Master's Degree in environmental science. Her experience reviewing scientific research and monitoring vital signs helped her test and compare these devices. Clark consulted with a professional freediver, Ryan Reed, to test many of these pulse oximeters in hypoxic conditions. Clark also consulted with two Black women to try the devices on darker skin tones and to gain additional perspectives on how easy, comfortable, and accurate each model is to use.
While pulse oximeters are, generally, quite similar to one another, we teased apart minor differences in fit and performance to find the best.
We tested these devices side-by-side.
Some of the monitors have more forgiving hinges than others. The AccuMed is in the middle of the road comfortwise.
Analysis and Test Results
We gathered real-world data from healthy testers to identify the most outstanding pulse oximeters for your needs. Our detailed data and use notes helped us compare the devices head-to-head. Below, we expand upon each testing metric, outlining which models excelled in each area.
Value
Pulse oximeters vary wildly in price, which is why we highly recommend the Innovo Deluxe iP900AP. It's affordable, easy to use, and more accurate than average, though it doesn't quite reach the accuracy levels of the pricier prescription options. If your doctor recommends a prescription-grade model for maximum accuracy, the Nonin is likely worth the cost.
Accuracy and Consistency
To know your true oxygen saturation rate, you need to find your arterial blood gas using a blood sample from an artery. This is a painful and somewhat risky procedure, and we didn't test these pulse oximeters by this high standard. But others have. They found that the Nonin provides more accurate readings than most when blood oxygen levels are low.
Of the two, the Nonin Onyx has more research backing its efficacy. Research also supports its claim that it provides more accurate readings for those with darker skin tones than other options. It is the only FDA-approved medical device in this review. The other pulse oximeters we reviewed are meant for wellness checks for athletes or aviation use. They're meant to be used by relatively healthy people and are not technically medical devices.
Pulse Oximeter Limitations
Pulse oximeters send beams of infrared light into your fingernail's capillary bed to measure changes in light absorption in your blood, indicating how much oxygen it's carrying. Skin color, thickness, circulation, skin temperature, and even nail polish can affect their accuracy.
A 2022 study published July 11th on JAMA Internal Medicine and covered by NPR found that relying on pulse oximeter readings lead intensive care staff to administer less oxygen to Asian, Hispanic, and Black patients than to white patients. The NPR article mentions that new technologies may soon address this very important failing.
A 2020 study in The New England Journal of Medicine found that hospital-grade pulse oximeters were three times as likely to miss low oxygen levels in Black patients than in light-skinned patients, missing it in around 11% of Black patients and 4% of White patients.
The New York Times ran an article responding to the 2020 study. They interviewed doctors who argued that pulse oximeters can still be a useful tool to monitor oxygen levels as long as you understand their limitations. It's a good idea to reach out to your doctor for more information on these complex topics.
Considering the research, we rank the Nonin Onyx as the most accurate monitor in our review. When we tested each monitor against the Nonin, they all gave us comparable oxygen saturation numbers — within one percentage point. In general, our testing found that these devices work well for healthy people with good circulation.
We used the Nonin pulse oximeter as an accuracy standard due to its medical-grade FDA approval and the multiple research studies backing its performance.
Credit: Clark Tate
Pulse Oximeters and COVID-19
The FDA issued a warning about the limitations and accuracies of pulse oximeters, stating:
While pulse oximeters may be useful for estimating blood oxygen levels, these devices have limitations that can result in inaccurate readings. Patients with conditions such as COVID-19 should not rely solely on pulse oximeter measurements to monitor their health at home as they are not a substitute for a medical diagnosis by a health care provider.
We think the same New York Times article that responds to the pulse oximeter racial bias study provides additional context.
Though many of these devices specify that they are for spot use and not for continuous monitoring, we wore each for five minutes and recorded their readings every minute. Most of the devices were consistent throughout the test and gave us average readings of 98% or 99%.
The Wellue O2Ring and iHealth were a bit lower, averaging 96% and 97%, respectively. Just know that these may give you lower readings on average. We also had trouble getting consistent results with the Oxiline Pulse XS Pro over the course of five minutes, with the SpO2 reading dropping from 99% to 94% and then rising a bit to 96%. The device feels a little tight and may restrict circulation over time.
We extensively tested and compared the top pulse oximeters. The Masimo performed well.
Credit: Clark Tate
What Should Your SpO2 Be?
Normal readings range between 95% and 100% according to the Mayo Clinic. According to Yale Medicine, readings below 92% are a sign of hypoxia, and any reading below 88% should spur you to seek immediate attention.
We did test the device's performance in hypoxic events on light-colored skin with the help of a professional freediver, who conducted several rounds of dry, static breath-hold training (from 2.5 to 3.5 minutes) with each device. We tested the devices in pairs to have a comparison point; most dipped to between 80% and 88% SpO2. The Wellue O2Ring, Wellue SleepU, and Innovo were more reactive than the others, tracking changes more closely.
The Walgreens Fingertip pulse oximeter nailed our accuracy tests.
Credit: Clark Tate
Ease of Use
We tested a wide range of pulse oximeters, from high-tech to superbly simple. While none of them are difficult to use, four of the options that link to your smart device via Bluetooth are more complex.
The Wellue SleepU and Wellue O2Ring options use the same ViHealth app. We find it easy to navigate, even when toggling between the two devices. It clearly displays readings in real-time and makes it easy to scroll through your history. The readouts on the devices themselves are harder to see.
The ViHealth app clearly tracks your oxygen levels (SpO2), pulse rate, and perfusion index (PI) in real-time.
The ViHealth app also charts continuous readings that are easy to access via the history tab. Here you can see one of the breath-hold tests of the professional freediver tester.
We struggled more with the Masimo Personal Health app. It doesn't catalog past recordings clearly by date, though it works well in real-time. The display is large, easy to read, and rotates to face you or a caretaker. The iHealth Air Wireless app is bright and cheery and maps long-term trends for you. We also like the on-device display. The problem with this pulse oximeter is how often the display blanks out.
The Oxiline Pulse XS Pro works with the streamlined MedM Health app, though we were disappointed that the box, directions, and website failed to clearly mention it by name. We had to Google what the app is called. Both it and the device are easy to use.
The Wellue wrist and ring options share an easy-to-use app that records data in real-time or the next time you sync with your smart device. It's much more pleasant than trying to decipher the readings on those tiny screens.
Credit: Clark Tate
Of the app-free options, the Nonin is one of the simplest. It turns on automatically and offers the fastest response time, giving you a reading in just over three seconds on average. The rest are similarly simple — you just need to press the power button first. We appreciate the Innovo, Walgreens Fingertip, Oxiline 9S Pro, Oxiline Pulse XS Pro,Mibest OLED Finger Pulse, Santamedical Generation 2 OLED, and Zacurate Children options that let you rotate their display, so it's easy for you to look at it no matter what finger you place it on.
It doesn't impact accuracy, but the polar bear on the Zacurate Children's monitor certainly affects wellness.
Credit: Clark Tate
Features and Versatility
All of these pulse oximeters measure your blood oxygen saturation and pulse rate. Quite a few include more detailed information. The Masimo MightySat offers the most comprehensive data, measuring SpO2, pulse rate, perfusion index (PI), respiration rate (RRp), and pleth variability index (PVi). It also stores everything in its companion app.
Having an app to store your data is a big plus, particularly if you're not good at documenting your measurements. Apps also emphasize interesting data like any concerning oxygen level drops. For that reason, we rate the MightySat quite highly. The Wellue O2Ring Wearable, Wellue SleepU wrist-mounted monitor and the iHealth options are high in the features category as well, thanks to their user-friendly interface and apps. The Wellue Fingertip stores 12 readings in the device itself, an intermediary step that we appreciate.
Most of these devices are only meant to take a spot check, measuring your pulse rate and Sp02 level at a single moment in time. All three Wellue options are also meant to monitor your oxygen profusion continuously. The fingertip version allows you to toggle back and forth between a spot check or continuous monitoring setting.
The ViHealth app records data from the Wellue USleep while you snooze. This device is, by far, the best in our review for continuous monitoring.
Credit: Ally Meller
A number of these devices also give you information — like a perfusion index score, a pulse rate bar, and a waveform photoplethysmograph — to help you determine if you're finger has enough blood flow for an accurate reading. The Innovo monitor gives you all three indications, as does the MightySat and the two Oxiline options. The AccuMed CMS-50D Fingertip and Santamedical give you the pulse bar and the waveform. The iHealth gives you your perfusion index in its app readout, and the Nonin, Mibest, Wellue Fingertip, and two Zacurate options provide a pulse bar.
What Do All of Those Numbers Mean?
Basic models offer just a couple of data points, and fancier devices often provide more. To understand the data, you'll need to know these abbreviations:
SpO2 stands for oxygen saturation. SpO2 measures the amount of oxygen in your blood at a given time. It is measured as a percentage of the total oxygen your blood is capable of carrying.
PR or HR stands for pulse rate or heart-rate, respectively. They are interchangeable and describe how many times your heart beats every minute. Your PR will change constantly based on your body position, activity level, or emotional state.
PI or perfusion index describes how much blood is in your non-pulsatile or peripheral tissues. A low PI number may indicate that you don't have enough blood flow in your fingers for an accurate reading.
PVi stands for pleth variability index. Pleth is short for photoplethysmograph. The pleth waveforms are the waves that show up on the bottom of some of the monitor displays. The pleth waveform indicates the strength of your pulse and how much blood is moving through your capillaries.
Brpm stands for breaths per minute or respiratory rate. It measures how many breath cycles you take every minute. It can reflect how well your heart and lungs function in day-to-day movement or while recovering from exercise.
The MightySat tracks your blood oxygenation, pulse rate, perfusion index, respiration rate, pleth waveform, and pleth variability index. It also has a companion app to track it all for you.
Credit: Clark Tate
Comfort
Even if you just have the device on your fingertip for a minute or two, you might as well be comfortable. If you need or want to monitor your oxygen level trends over time, you'll appreciate not feeling like your finger is in a vice.
The Wellue O2Ring and SleepU monitors are meant to monitor your pulse and oxygen levels while you sleep. They are exponentially more comfortable than their fingertip clip counterparts. Of the two, we prefer the wrist monitor since it divides its weight and bulk between your finger and wrist. Still, we don't mind sleeping with either device or wearing them for hours during the day.
The MightySat's clever hinge relieves pressure on your fingertip, and its padded finger cradle is as comfy as they come.
Credit: Clark Tate
The MightySat is the most comfortable of the fingertip monitors. The hinge spreads pressure evenly across your first two joints instead of concentrating it at your fingertip. The cushioned port is really nice — this is the only hinged monitor we would want to wear for any amount of time.
The rest are fine. Certainly comfortable enough for a speedy spot check. The iHealth monitor is among the least comfortable in the review since it forces you to find a comfortable palm-up resting position.
The short and simple models in the test are comfortable enough, but aren't long enough to distribute their pressure along your finger, leaving it concentrated in your fingertip.
Credit: Clark Tate
Quality
To gauge material quality and durability, we rolled these devices around on our fingers, tugged on the hinges, and looked closely at the battery door tabs. In general, they are robust devices that will perform their task reliably if you treat them as well as a smartphone.
The fingertip monitors seem more robust than the wearable options. Both the Wellue SleepU and O2Ring have a ring monitor that is not meant to be compressed, so don't sit on them or toss them in a bag. We saved the boxes they came in for safekeeping.
With a springloaded battery compartment, robust hinge, and scratch-free facade, we expect the Nonin to last.
Credit: Clark Tate
Of the clip-style monitors, Innovo strikes us as particularly robust and well-made. Its battery door tabs and hinges are easy to operate, the hinge is well-contained, and the plastic feels sturdy. We are pleased with how the screen shrugged off inevitable scratches and wear. The Nonin seems to be of similarly high quality, with a pleasant spring on its battery door and scratch-free facade. We also appreciate that the AccuMed and Zacurate options come with protective rubber covers.
The Innovo feels solid, with a well protected hinge, an easy to open battery port, and a scratch-resistant screen.
Credit: Clark Tate
Most of the remaining monitors give us little cause for concern. The AccuMed's screen received a few scratches. And while the MightySat seems very well-made, the battery door is hard to open and seems like it could easily break. The iHealth hinges chattered a bit, often closing a little out of line.
Don't forget your mask
Contagious respiratory illnesses like the flu and Covid-19 can affect your oxygen levels. Wearing a face mask when these viruses are circulating in your community could help you avoid the issue.
We tested a pile of pulse oximeters to help you narrow down all the choices on the market.
Credit: Clark Tate
Conclusion
The quest for a pulse oximeter can feel complicated, given the scientific jargon and many abbreviations. We're here to help. To pick the best monitor for your needs, figure out when you'll use it and why. From there, you can decide which features are right for you. Good luck and good health.
