Which Smartwatches Have ECG and AFib Detection in 2026?

The ability to record an electrocardiogram from your wrist went from science fiction to a $250 feature in about eight years, and it is now the single most-searched health capability in the category. But the market is confusing: not every watch that shows a heart rate can record an ECG, not every ECG feature is cleared by a regulator, and the phrase “AFib detection” gets used for two genuinely different features.

Here is the current picture in 2026 — which smartwatches with ECG and AFib detection are actually cleared, what the clearance does and does not mean, and how to read a notification without either panicking or ignoring it.

Important: this article is general information about consumer device features, not medical advice. No smartwatch diagnoses a heart condition. If you have symptoms or a notification concerns you, contact a healthcare professional.

The Two Features People Confuse

Almost every question about this topic dissolves once you separate these.

Irregular rhythm notifications run in the background. The watch uses its optical (green light) heart rate sensor to sample your pulse periodically, looks for the irregular pattern characteristic of atrial fibrillation, and notifies you if it sees it repeatedly. You do nothing; it watches passively. It is a screening tool, and it is the feature most likely to catch something you did not know about.

The ECG app is active. You open it, hold a finger on the crown or the opposite sensor to complete a circuit across your heart, and hold still for about 30 seconds. The result is a real single-lead waveform, classified as sinus rhythm, atrial fibrillation, high or low heart rate, or inconclusive. You can export it as a PDF.

A useful way to think about it: the passive feature tells you when to look, and the ECG is the look. Buying a watch for the ECG app while switching off the background notifications gets the value backwards.

Apple

Apple has the widest coverage and the longest track record here.

ECG: Apple Watch Series 4 and later, and every Apple Watch Ultra. The current Series 11 and Ultra 3 carry improved rhythm classification and richer AFib history reporting.

Irregular rhythm notifications: Series 6 and later cover the current feature set most completely.

AFib History: if you have already been diagnosed with AFib, this feature estimates how often you were in it and tracks lifestyle factors alongside it. This is the most genuinely clinically useful part of the package, and it is the one people know least about.

What is missing: the Apple Watch SE line — including the current SE 3 — has no ECG electrode and no ECG app. This trips people up constantly, because the SE 3 shares nearly all of the Series 11’s software. If ECG is why you are buying, the SE is not the watch.

Apple added hypertension notifications to the current generation as well, which is a separate feature from anything ECG-related but often gets bundled into the same conversation.

Apple Watch Series 11 on Amazon

Samsung

ECG and irregular heart rhythm notifications: Galaxy Watch 4 and later, including the current Galaxy Watch 8 and Watch 8 Classic, via the Samsung Health Monitor app.

Two practical catches specific to Samsung. First, the Samsung Health Monitor app is only fully supported when the watch is paired with a Samsung Galaxy phone — pairing a Galaxy Watch with a non-Samsung Android phone historically limits access to ECG and blood pressure features. Second, blood pressure measurement, which Samsung offers in some markets, is not cleared in the United States, so the feature set differs by country more than on any other brand.

Reported sensitivity for AFib detection against clinical ECG is high — figures in the high 90s are commonly cited — but as always those numbers come from controlled testing rather than daily wear.

Samsung Galaxy Watch 8 on Amazon

Fitbit

Fitbit’s ECG story is narrower than people expect, because most Fitbit devices do not have the feature.

Fitbit Sense 2 — full ECG app plus irregular heart rhythm notifications, and around six to seven days of battery, which is by some distance the longest of any ECG-capable watch on this list.

Fitbit Charge 6 — this is the notable one, because it is a band rather than a watch and it still carries the ECG app. If you want ECG in the smallest and cheapest possible package, this is it.

Everything else in Fitbit’s range — the Inspire line, older Versa models, the Luxe — does not have ECG hardware. Since Fitbit’s platform now underpins the Pixel Watch as well, it is worth noting that Pixel Watch models carry irregular rhythm notifications and an ECG app through the same infrastructure.

Fitbit Sense 2 on Amazon

Withings

The one most people have never heard of, and the one cardiologists mention most often for patients who do not want a screen on their wrist.

The ScanWatch line looks like an analog watch — real hands, a small subdial, a tiny circular display — and records a single-lead ECG by touching the bezel. Battery life runs to around 30 days, which changes the whole proposition: a device you never think about charging is a device that is actually on your wrist when an episode happens.

That is the strongest argument in the entire category and it belongs to the least-marketed brand in it. If your goal is long-term monitoring rather than a smartwatch that also does ECG, start here.

Withings ScanWatch on Amazon

What FDA Clearance Actually Means

This is where most coverage is sloppy, so it is worth being precise.

Cleared is not approved. These devices go through the FDA’s 510(k) clearance pathway, which establishes that a device is substantially equivalent to an existing legally marketed one. It is a real regulatory bar, and it is a lower one than the premarket approval process used for high-risk medical devices.

Clearance is for a specific claim. The claim is roughly “can record a single-lead ECG and can classify a rhythm as AFib or sinus rhythm in people 22 and over without a prior AFib diagnosis.” It is not a claim to diagnose, to rule out a heart attack, or to detect other arrhythmias. A watch that says “sinus rhythm” is telling you nothing about whether you are having a heart attack — a distinction the manufacturers state clearly and users routinely miss.

Clearance is market-specific. A feature cleared in the US may be unavailable in another country, and vice versa. Device settings sometimes disable ECG based on your region.

Single-lead is not twelve-lead. A clinical ECG uses twelve leads placed around the torso and limbs and can see the heart from many angles. Your watch has one. It is enough to see rhythm; it is not enough to see most of what a cardiologist looks for.

How Reliable Is It in Real Life?

Under laboratory conditions with a still, warm, correctly-fitted wearer, these devices perform well. Everyday accuracy is lower, and the reasons are mundane:

• Fit. A loose band is the single biggest cause of bad readings. The watch should sit snug, about a finger’s width above the wrist bone, and tighter during a reading.
• Cold hands. Reduced peripheral circulation degrades the optical signal that powers the background notifications.
• Motion. Any movement during the 30-second ECG will produce an inconclusive result.
• Tattoos and skin tone. Dense ink under the sensor blocks the optical signal outright. Sensor performance across skin tones remains an active area of research, and it affects the passive features more than the electrical ECG.
• Intermittent AFib. The hardest problem of all. If your AFib comes and goes, a reading taken while you are in normal rhythm is correctly negative and tells you nothing about the episodes you are having.

The broader question of how much to trust any wrist sensor is worth understanding before you rely on one — we covered the research in how accurate are smartwatch heart rate monitors.

What to Do If You Get a Notification

Not medical advice, but the sensible sequence is straightforward:

1. Do not panic, and do not dismiss it. Irregular rhythm notifications fire relatively rarely; they are not routine noise.
2. Take an ECG reading if your device has one, sitting still, arms resting on a table. Take a few over the following days at different times.
3. Export the PDFs. Every one of these platforms lets you save readings as a PDF from the phone app. This is what makes the feature clinically useful — you are handing a clinician data, not a story.
4. Book an appointment. Bring the recordings. A watch notification is a legitimate reason to be seen.
5. Seek urgent care for symptoms — chest pain, fainting, severe shortness of breath — regardless of what the watch says. The device has no ability to assess any of that.

Which One Should You Buy?

• Already on iPhone, want the most complete package: Apple Watch Series 11. AFib History is the differentiator if you have a diagnosis.
• Already on a Samsung phone: Galaxy Watch 8. Same features, better battery, but keep the phone-pairing limitation in mind.
• Want the longest battery in an ECG device: Withings ScanWatch, comfortably. Around 30 days versus roughly one.
• Want the smallest and cheapest: Fitbit Charge 6 — a band, not a watch, with the ECG app intact.
• Buying primarily for sleep and recovery, with heart health secondary: look at smartwatches that detect sleep apnea and best smartwatches for sleep tracking instead — different sensors, different priorities.

If you are choosing a watch generally and ECG is only one factor among several, our best smartwatches of 2026 guide weighs it against battery, price and ecosystem. And for the related question of blood glucose — the feature everyone keeps expecting — see will the Apple Watch add blood glucose tracking.

Compare ECG smartwatches on Amazon

Feature availability and regulatory clearance are accurate as of August 2026 and vary by country. This article is general information, not medical advice.