Learn what an ECG can tell you, how the technology works, and which smartwatches offer the feature.

With heart rate monitors now standard in smartwatches and fitness trackers, electrocardiograms (ECG/EKG) have rapidly become a common feature in health wearables.

The technology is designed to help people keep closer tabs on their heart health and is used to help identify atrial fibrillation (Afib), a serious medical condition that is a leading cause of stroke.

ECG was thrust into the wearable spotlight via the Apple Watch Series 4 in 2018, but it can now be found on smartwatches from Samsung, Google, Fitbit, Huawei, and Garmin.

What is ECG, and why is it a useful feature for a smartwatch? We discuss all of the key details below.

Read next: Best smartwatches reviewed and rated

ECG smartwatches: FAQs

What is ECG?

Most wearables have optical heart rate monitors, which use flashing LEDs to penetrate the skin and detect blood flow. When light is reflected off the flow of blood, it’s captured by the sensors.

The algorithm processes the data to estimate your heart rate. However, its accuracy may be limited, particularly when there are medical concerns. This is where the electrocardiogram (ECG or EKG) comes in. Instead of measuring blood flow, the ECG is designed to assess the heart’s performance.

It’s a term you’d more commonly hear in the medical industry, referring to an electrocardiograph that’s used to detect cardiac abnormalities.

Why buy an ECG smartwatch?

An ECG smartwatch can detect atrial fibrillation, a condition that leads to an irregular heart rate and is a significant cause of strokes. Taking an ECG reading on your watch can help determine if you have a healthy heart rhythm.

However, many people may only use this feature once and then forget about it. For a substantial number of individuals, having ECG capabilities can be extremely beneficial. Smartwatches from brands like Apple and Fitbit can export an ECG graph of your heart rate, which can be very helpful when discussing your health with your doctor.

“ECG on wearables is super high value for a small segment. It is probably going to be more advantageous to our users over 50 than 20-year-olds, but we’re trying to build something for everybody,” Dr. Conor Heneghan, Director of Research Algorithms at Fitbit,

told Wareable.

“Afib can come and go, as can conditions that affect the rhythm of your heart. That means having a device that can take spot readings at any time, makes it a hugely powerful health tool to have at your disposal,” he said.

How do ECG smartwatches work?

Most watches have a built-in ECG sensor, that can take a spot reading of your heart rate rhythm.

You start the app and then place your finger on a specific part of the watch (usually the case or crown) for the duration of the test.

Fitbit has recently launched a new feature that continuously monitors heart rate rhythms, and can look for atrial fibrillation using the PPG sensor.

While this has an advantage over ECG watches for spotting Afib, ECG smartwatches offer the benefit of being able to export a graph of your heart rate rhythm.

How often should I take an ECG reading?

Provided your heart gets a normal sinus rhythm, you’re likely to only need to periodically take an ECG test, just to check everything is in order.

But if you suffer from the feeling of your heart racing, palpitations, or periods of feeling unwell, then you can use the ECG app as and when you need it. And it becomes an incredibly important health tool, right on your wrist.

Fitbit’s Director of Research Algorithms, Conor Heneghan, says that means users can have a better-informed conversation with their doctor.

“The problem with cardiac issues with rhythm is they’re so intermittent,” said Heneghan.

“For people who have palpitations or other symptoms, ECG can be a reassurance. And if they feel like something’s a bit odd going on physiologically they can capture that moment to speak with their doctor about it,” he continued.

Fitbit also recommends that the ECG feature should only be used by those aged 22 or above.

Best smartwatches with ECG in 2025

The following is the list of current-gen smartwatches that include an ECG function.

You can click through to our full, in-depth reviews of each and read what we thought of the ECG functionality. We’ve also grouped them together and discussed how each brand handles ECG readings in the section below.

ECG watches and wearables available today

While ECG was once a premium feature reserved for flagship wearables, it’s now present in multiple devices from each brand. Given that the feature almost always works identically across an ecosystem, we’ve grouped the current devices with ECG from different manufacturers and explained how it works.

Apple Watch Series 4-10 | Ultra 1-2

apple-watch-ultra-ecg — Credit: Wareable

The latest Apple Watch Series 10 and Ultra 2—plus older models—boast ECG functionality, with sensors built into the ceramic heart rate monitor under the watch and the Digital Crown.

Fire up the ECG app, pop your finger on the crown, and you’ll be guided through the reading.

You’ll be notified whether the reading is regular or shows signs of atrial fibrillation, and an EKG graph of your heart rate will be logged in the Apple Health smartwatch app, which can be downloaded and shared with your doctor.

Apple has FDA approval for its ECG and clearance in the European Economic Area, and more than 20 countries now have the ability to use the health feature.

How to use the Apple Watch ECG feature

Samsung Galaxy Watch (all models)

The Galaxy Watch 7 is the latest and greatest Samsung smartwatch in town, and ECG measurement is still a big part of its appeal. However, you will need a Samsung smartphone to use the feature.

The ECG app is available on the Galaxy Watch 7 and Ultra, as well as the Watch 6 Classic, Watch 5, Watch 5 Pro, Watch 4, and Watch 4 Classic.

When you place your finger on the sensor built into the top physical button, it takes a 30-second reading. You’ll also need to remain still with your forearm resting on a flat surface.

Samsung’s Health Monitor app is live in the US and South Korea, and it’s also received clearance in Europe.

Specifically, it’s available in Iceland, Germany, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, Finland, France, Hungary, Ireland, Italy, Latvia, Belgium, Lithuania, Netherlands, Greece, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Austria, and the United Kingdom.

Moreover, Japan, Indonesia, UAE, Chile, India, and China are all confirmed, too.

Fitbit Sense 2 | Charge 6 (and previous generations)

The Fitbit Sense 2 stands as the sole health watch from the company, equipped with various sensors, such as ECG. However, it’s also available on the Charge 6 fitness tracker.

It’s the only fitness tracker form factor capable of taking an ECG reading, making it a great option for people who prefer not to wear a smartwatch. To take the reading, you pinch the sides of the case, and the data is sent to the Fitbit app.

With the Sense 2, users can perform ECG spot checks by opening the app, touching their fingers to the aluminum case, and holding as instructed on the watch for an ECG to be taken. Again, this can be exported via a PDF.

The PPG sensor also continuously scans for abnormal rhythms, including high and low heart rates. That means it can alert you to possible issues without taking manual scans, and if you suffer from a condition, you can better understand potential triggers.

The Fitbit ECG sensor has gained entire FDA and CE approval for use in the US and Europe.

Google Pixel Watch 1-3

google-pixel-watch-3-review-app-drawer — Credit: Wareable

It’s not just Fitbit’s devices that Google enlists to take electrocardiograms, with the Pixel Watch 3 (and the original Pixel Watches) also offering the skill.

Like with the Apple Watch, this is taken through the crown on the outer edge of the watch through a 30-second scan.

Results are then sent to the Fitbit app for your perusal, with a full history and timeline of your readings shown.

Huawei Watch 4 | Watch GT 5 Pro

Huawei now has a regulatory sign-off for its ECG feature in Europe, and you can perform heart rate rhythm spot checks on its newer smartwatches.

It’s been added to the current flagship, the Huawei Watch 4 series, and is also available on the newer upper mid-range Watch GT 5 Pro and the Watch D2 (below).

Taking a heart rate measurement will show you whether your heart rhythm is normal or Afib on the watch, and save a result to Huawei Health.

In the app you can also log any accompanying symptoms and see an ECG graph, which can be shown to your doctor, to assist in any conversations.

Huawei Watch D2

We’ve split off the Huawei Watch D2 because it’s such a drastically different proposition to the other Huawei devices featuring ECG. This is the brand’s dedicated health watch, which offers blood pressure monitoring and ECG detection, and it’s a serious health watch.

It’s certainly not a comfortable, sleek smartwatch for casual wear, but as we discovered in our review, it’s a practical health smartwatch. This device is designed for medical-grade surveillance of your vitals, and it’s likely suited to those with a pre-existing condition.

As with all things Huawei, we are unlikely to see a release for this one in the US.

Garmin Fenix 8 | Venu 3 | Enduro 3

After introducing the feature relatively late, Garmin now has many watches within its stable capable of running the ECG feature.

At the time of writing, this list encompasses the Garmin devices with the Elevate 5 heart rate sensor, given this also packs in the required architecture for an ECG reading. This includes the Fenix 8, Fenix 7 Pro, Epix Pro (Gen 2), Enduro 3, Venu 3, and Venu 2 Plus.

Garmin’s ECG feature is now available in many countries, including most major EU nations, Australia, and the US. The UK, Canada, Switzerland, and New Zealand are a few notable exceptions.

The feature works by having the user place their index finger and thumb on the metal edge of the device’s bezel or on the top-right button for 30 seconds to obtain a reading. The watch will display the heart rate rhythm and indicate whether it is sinus (normal) or Afib.

You’ll need to set it up in Garmin Connect first, which will also serve as a hub for historical data and a place where you can export individual readings as PDFs.

Everything you need to know about the Garmin ECG feature

Withings ScanWatch 2 | ScanWatch Light | ScanWatch Nova

Withings ScanWatch 2 ecg — Credit: Wareable

The Withings ScanWatch 2 and ScanWatch Light are the company’s current-gen hybrids, along with the more premium Nova and Nova Brilliant models. These are among the top hybrid watches on the market, with a skew toward health and wellness monitoring instead of fitness tracking.

The ECG feature works similarly across the board here, and it’s still one of the most proactive we’ve tested in this regard. You can take off-the-cuff ECG readings to check for AFib; the results can be presented in a PDF to show to your doctor. It will also look for irregular heart rhythms.

The optical heart rate sensor checks your heart rate throughout the day for irregular beats, and if it thinks you may have them, it will suggest that you take an ECG test.

There’s not too much difference between the core ScanWatch models, with the premise and broad design being the same. The Light is the more budget-friendly alternative to the ScanWatch 2 (above), and the Nova editions are more expensive, but the tracking experience is much the same.

Coros Vertix 2 | Apex 2/2 Pro | Pace Pro

Coros is slowly beginning to expand its ECG functionality to more watches. The Pace Pro, released in late 2024, is the latest (and first) of the brand’s running watches to get the feature. However, it’s also been a part of the Vertix and Apex ranges for some time, including on the most recent second-gen models.

However, it’s not a health feature like those found on other smartwatches. Instead, the Coros sensor is designed to provide a more accurate assessment of heart rate variability, which is used to gauge your recovery after workouts. Poor HRV scores can also indicate stress, overtraining, or alcohol intake.

HRV scores are commonplace in fitness wearables but are usually measured via the PPG sensor during sleep. We like that Coros has gone down a novel route that aligns with the brand’s specialty.

How does ECG smartwatch tech work?

An ECG captures the small electrical signals produced by your heart’s beats beneath the skin, displaying them as a trace. This enables trained professionals, devices, or wearables to gain insights into your heart’s function and identify any potential abnormalities.

“In the simplest sense, it can tell you the heart rate (how fast), the rhythm (how regular), the state of the conduction system and muscle tissue (heart attacks), and even the level of certain chemicals like potassium in the blood, and the effect of medication,” says Dr. Keith Grimes, GP and Clinical Innovation Director at Babylon Health.

In a medical environment, an electrocardiograph typically involves attaching electrodes to the skin near the heart. This setup measures the electrical activity generated during heart contractions. The gathered electrical signals are transmitted to a receiver that records the data, allowing for an analysis of the heart’s rhythm and identification of any irregularities.

What about ECG readings in consumer devices?

The technology in the Apple Watch (and other at-home ECG devices) functions differently.

Instead of applying electrodes to your skin, the Apple Watch requires you to touch your finger to the digital crown. After waiting for 30 seconds, your heart’s electrical activity creates a red trace on the watch screen. When finished, the app will inform you if the trace shows a normal heartbeat, known as a sinus rhythm, or an irregular heartbeat.

On the Fitbit Sense, once you open the ECG app, you’ll be prompted to place your fingers on the corners of the watch’s frame for 30 seconds to take a reading. It will then indicate whether you have a normal sinus rhythm, if there are signs of atrial fibrillation, or if the reading is inconclusive.

Samsung’s ECG-equipped smartwatches utilize a touch-sensitive button that you place your finger on for 30 seconds. Afterward, they measure your heart rate and rhythm, classifying it as either normal sinus rhythm or AFib.

The biggest difference between an electrocardiograph at a hospital and the ECG technology in your Apple, Fitbit, or Samsung smartwatch is that the former uses 12 leads while the latter uses a single lead. In the simplest terms, the 12-lead device takes multiple readings of your heart, while the single lead takes just one.

samsung health on a watch — Credit: Wareable

A single lead ECG has limited capabilities and provides just one view of your heart. It cannot reliably detect all heart rhythm abnormalities or worsening heart problems. Additionally, it cannot identify the electrical changes that occur during a heart attack or reveal an abnormal heart structure.

Apple clarifies this, but it’s important to distinguish between the benefits of an ECG performed in a hospital and those provided by home technology.

How can ECG tech save your life?

huawei-watch-gt-5-pro-ecg — Credit: Wareable

An ECG performed by a medical professional can detect various heart issues. However, ECG devices intended for home use are not quite fully developed yet.

Here are several ways the ECG technology in your Apple Watch or Samsung smartwatch can currently save your life, including the issues it can identify and those it may be able to.

Atrial fibrillation

Atrial fibrillation is a heart condition characterized by an irregular and rapid heartbeat. This common condition can be life-threatening. Its intermittent nature adds to the challenge of detection. Notably, both Apple and Samsung have received FDA clearance to identify this condition, while Fitbit’s new Sense watch is still awaiting FDA approval for similar capabilities.

ZDNet writer Jason Perlow participated in the early testing of Apple’s Atrial fibrillation detection and, thanks to the data collected, identified a problem with his heart in 2018.

The reason personal devices are effective at recognizing this particular kind of arrhythmia (irregular heartbeat), and the reason Perlow cites for its effectiveness in his case, is because you can take them at any time.

Unlike getting an ECG at the hospital, you can monitor your heart throughout the day. “Irregularities in heart rate can be episodic, and difficult to capture,” explains Dr. Grimes, “So a personal ECG that you carry with you can help clinicians record when palpitations happen and help with diagnosis.”

This means you can take a 30-second ECG whenever you feel symptoms and also better understand the context of what may have brought them on. For example, if you just got back from a run and you’re feeling a bit off.

Advice on harnessing the ECG feature

Dr. Tony Faranesh, a senior research scientist at Fitbit says the optimal way to identify atrial fibrillation through heart rate tracking is to screen while at rest, making sleep ideal for detection.

On Fitbit’s devices, that’s done by using its optical-based PPG heart rate sensor. The ECG sensor, like Apple and Samsung, is used for spot checks.

Like Apple, it seems that Fitbit won’t be continually scanning for signs of Afib, though Apple and Fitbit both use the PPG sensor to check for irregular rhythms such as high or low heart rate.

Dr. Julia Reynolds, Associate Director at Innovation Agency, tells us that the Kardia Mobile built by startup AliveCor is sometimes even prescribed to patients for this exact reason.

“Individuals may be given a mobile ECG device by their health professional if they are concerned they may have paroxysmal Atrial fibrillation – that’s when it comes and goes. That way, if they are feeling signs and symptoms, they can take their ECG when they are experiencing symptoms.”

The problems with false positives – and negatives

ECG devices available to consumers can detect a range of heart problems, whether cleared or not, but that doesn’t mean they should replace a trip to your doctor.

“Reading an ECG is tricky,” Dr. Grimes explains. “Current technology uses machine learning to detect common abnormalities, but personal ECG, like the kind you find on the Apple Watch, is not as accurate as medical devices.”

Personal ECG devices are proven to save lives, but on the flip side, they can still miss major problems or cause people to worry they have heart issues when they don’t. Dr. Grimes calls these “false negatives” and “false positives.”

Although many in the medical profession are warning people to be wary of the results they get from their Apple Watch or other ECG devices, having more control over our health at home will become more widespread over time.

That means instead of advising against ECG devices, people need to be informed that readings might not always be accurate. If you see a reading you’re concerned about, it’s best to head to a medical professional to get it checked out.