The 5 Best Pulse Oximeters of 2021

From COPD to sleep apnea, these devices can help you track your health at home

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First Look

Best Overall: Contec CMS50DL at Amazon

"In addition to being accurate, this device is simple to operate—you just have to turn it on, slip it on, and wait for a reading."

Best Budget: Zacurate Pro Series 500DL at Amazon

"It reads both blood oxygen saturation levels and heart rate and delivers both in an incredibly simple, read-at-a-glance visual display."

Best Ring: Wellue O2Ring at Amazon

"If you have sleep apnea or COPD where your doctor might want you monitoring your oxygen levels overnight, the ring will stay on your finger better than a clip-on."

Fastest Results: CMS-50 D Plus at eBay

"What’s especially cool about the CMS-50D Plus is it has the added feature of built-in flash memory."

Best for Kids: Acc U Rate Children Fingertip Pulse Oximeter at Amazon

"This pediatric version is made to fit the fingers of kids between 2 and 10 and is quite accurate in its readings."

Pulse oximeters have traditionally been used by nurses and clinicians, or for home monitoring with conditions like chronic obstructive pulmonary disease (COPD) or pulmonary fibrosis, says Lon Jones, D.O., author of Asthma and Allergy Solution that Works for COVID- 19. But with the rise of sneaky respiratory concerns like COVID-19, a growing number of physicians have started recommending more and more people keep a pulse oximeter at home.

The device is a painless, reliable way to check someone's oxygen saturation—or the amount of oxygen that's currently being pumped through your blood. A drop in numbers can be a sign of respiratory distress. Some physicians believe that with something like COVID-19, regularly spot checking your levels could be useful in the event that you have mild symptoms, but a sudden drop in your blood oxygen saturation could be an early warning bell to go see your doctor ASAP. 

The issue: Buying a pulse oximeter for your home can be quite tricky. A 2018 study in the European Respiratory Journal reports that overall, commercially-available pulse oximeters give an accurate reading of oxygen saturation—but how accurate varies among devices. Here are five of the best. 

Due to increased demand for online shopping, items in this article may be out of stock. Updates to this article will be made frequently with only products we recommend.

Our Top Picks

1

Best Overall: Contec CMS50DL

Pulse oximeter

When researchers at the University of California at San Francisco tested six low-cost finger pulse oximeters, the Contec CMS50DL was one of two that read oxygen saturation precisely enough to meet the International Organization for Standardization (ISO) criteria for accuracy. Plus, it's an FDA-approved medical device, so the standard of quality is there.

In addition to being accurate, this device is simple to operate—you just have to turn it on, slip it on, and wait for a reading. It measures your oxygen saturation through a finger sensor and displays both your blood oxygen saturation level as well as your average heart rate. 

The batteries are intended to last up to 24 hours, and the device shuts off automatically after five seconds to help battery life last longer.

Best yet, it’s one of the most affordable devices on the market. And with the cheaper price tag, you’re not giving up accuracy—just added features. If all you need is a quick oxygen saturation check, this device gets the job done better than most.

2

Best Budget: Zacurate Pro Series 500DL

Zacurate Pro series 500DL fingertip pulse oximeter
Courtesy of Amazon.

The Zacurate Pro 500DL has everything you need in a pulse oximeter: accuracy and reliability. 

It reads both blood oxygen saturation levels and heart rate and delivers both in an incredibly simple, read-at-a-glance visual display. Both the numbers face the user, which is great if you’re looking for a device you’ll take readings off of yourself, but can be annoying if a caregiver is the primary user.

The read-out isn’t the fastest—the device promises to deliver your numbers within 10 seconds. But the readings are accurate, within 2 percent of your blood oxygen saturation levels, which is standard for most high-quality devices. And the 500DL takes an equally accurate reading regardless of whether you're in natural lighting, indoors, or in a dark room (something their previous models struggled with). 

The device itself is made with a medical-grade silicone finger chamber, so it's hypoallergenic (particularly nice if you are sensitive to latex), that will fit most fingers over 12 years old. One set of batteries will last you 40 hours with this model, and it turns off automatically 16 seconds after you remove it from your finger.

3

Best Ring: Wellue O2Ring

Because this device looks so different than the typical pulse oximeter, it’s easy to write it off. But a landmark study in Clinical and Experimental Hypertension confirmed a ring-shaped pulse oximeter delivered just as accurate of an oxygen saturation reading as a standard pulse oximeter.

The Wellue O2Ring is one of the best ring options you can buy. The real draw is using it to sleep: If you have sleep apnea or COPD where your doctor might want you monitoring your oxygen levels overnight, the ring will stay on your finger better than a clip-on. (Docs note the ring should be used in conjunction with a CPAP machine, not in lieu of.)

It looks super high-tech and sleek, especially compared to other pulse oximeter rings. But moreover, it has a vibrating alert system, which is less alarming than a loud beep if your oxygen levels or heart rate drop too low in the middle of the night, but still jarring enough to wake you.

What’s more, the ring is bluetooth-compatible, connecting with a super clean app interface where you can customize which levels cause an alarm. The bluetooth also allows you to upload reports and share them with your doctor.

It certainly comes with a higher price tag than most pulse oximeters, but the technology is reliable and accurate and the device itself durable to last you longer than cheaper, finicky devices. It also comes with a 12-month warranty, which is nice to cushion the higher price tag.

4

Fastest Results: CMS-50 D Plus

CMS 50 Plus

As a foundational draw, this pulse oximeter has been cleared by the FDA as a Class II Medical Device so it’s accurate on monitoring your oxygen levels. Additionally, the device has all the basics you need in a pulse oximeter: A fingertip sensor, a digital display of your heart rate and blood oxygen saturation numbers, even a bar graph of your pulse for easy reference.

Then, it has a few added bells and whistles. For starters, it stays accurate at high altitudes, which isn’t the case for all models. This makes it ideal for people who live at altitude. Also, you can set up the device to sound an alarm when your pulse rate or oxygen saturation drops below a pre-set number or when it's not positioned correctly to give an accurate read.

What’s especially cool about the CMS-50D Plus is it has the added feature of built-in flash memory. It will record up to 24 hours of data. Just plug the device into your computer (USB cable included) and you can create a report with the included software. This is great if you're trying to keep track of oxygen saturation over time.

We also love that the display can be adjusted to be readable either horizontally or vertically, compared to most models where you’re always reading your numbers upside down (because they’re intended for the nurse opposite you to read).

5

Best for Kids: Acc U Rate Children Fingertip Pulse Oximeter

Most regular pulse oximeters will have a difficult time getting a read off the small, thin fingers of children. But this pediatric version is made to fit the fingers of kids between two and 10 and is quite accurate in its readings. And the face rocks a cute polar bear design, making medical readings a little less scary for your kiddo.

We love that the display is not only clear and bright for easy use, but also lets you rotate the direction of the numbers so it's readable from in front of your child or next to them. The Acc U Rate also reads heart rates, displayed via a plethysmograph waveform—essentially the most bare-minimum visualization of a heartbeat, so it's easy to read and interpret at a glance.

It can run up to 30 hours on one set of batteries (and there's a battery life on the display).

Final Verdict

If you need a basic pulse oximeter just to spot-check blood oxygen saturation levels for any kind of medical condition (or pandemic peace of mind), the Contec CMS50DL is the most reliable device with a wallet-friendly price tag that doesn't compromise accuracy. If you're looking for a device to monitor health concerns more than just one-off, it’s worth it to fork up for the Wellue 02Ring. It’s packed with more advanced technology, accurate sensors, and designed to stay on your finger as you move during sleep.

What to Look for in a Pulse Oximeter

Symptoms: With most respiratory issues—from COVID-19 to asthma—you're going to feel a disruption in your breathing before a pulse oximeter spot check alerts you to any problems, points out Daniel Murphy, MD, assistant professor and medical director of the Section of Internal Medicine at Baylor College of Medicine. The devices can be helpful for certain conditions if you have more mild symptoms and then suddenly a significant drop in blood oxygen saturation, but make sure you're paying attention to any warning signs from your body first and foremost.

Accuracy: There is a huge variation in the accuracy of commercially-available pulse oximeters. Look for those that are FDA approved, which doesn’t guarantee their precision but definitely gives them a leg to stand on. After, customer satisfaction ratings are really the only thing we have to go on, says Dr. Jones.

Variability: There is a huge variation in the accuracy of commercially available pulse oximeters, but there are other factors that can affect the accuracy of a reading. Keep in mind lighting in the room, nail polish, movement during a reading (even a small amount), and cold hands can all deliver inaccurate numbers, says Dr. Murphy.

Why Trust Verywell Health

Rachael Schultz is a freelance writer with a focus in health and nutrition. Her articles have appeared on a handful of other Health sites, and she has a degree from the Savannah College of Art and Design. She specializes in breaking down science and medical jargon into digestible information.

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  1. Mcdermott R, Liddicoat H, Moore A, et al. Evaluating the accuracy of commercially available finger pulse oximeters in a hospital settingEuropean Respiratory Journal. 2018;52 (suppl 62). doi:10.1183/13993003.congress-2018.PA4452

  2. Lipnick MS, Feiner JR, Au P, Bernstein M, Bickler PE. The accuracy of 6 inexpensive pulse oximeters not cleared by the food and drug administration: the possible global public health implicationsAnesthesia & Analgesia. 2016;123(2):338–345.

  3. Kishimoto A, Tochikubo O, Ohshige K, Yanaga A. Ring-shaped pulse oximeter and its application: measurement of SpO2 and blood pressure during sleep and during flightClin Exp Hypertens. 2005;27(2-3):279-288.