Health Technology
Quick Verdict
If you want one recommendation: the $79 KardiaMobile is the best first at-home ECG for most people, because it is FDA cleared for the same four determinations as the watches, it works with any phone rather than locking you to one brand, it has no age floor imposed by the manufacturer the way the watches do, and it needs no subscription. If a doctor has asked you to capture episodes to bring to an appointment, step up to the six lead KardiaMobile 6L instead, currently $114 against a $129 list price. If you already wear an Apple Watch or a Galaxy Watch, you already own a capable single lead ECG and you should not buy anything until you have used it.
Now the honest framing that most buying guides skip. Every device on this page records a fraction of a real ECG. A clinical ECG uses twelve leads. The best consumer device here uses six, the watches use one. What that buys you is a reliable answer to one narrow question, is this rhythm atrial fibrillation, and almost nothing else. Apple states in its own documentation that the ECG app cannot detect heart attacks, blood clots or strokes, high blood pressure, congestive heart failure, high cholesterol, or other forms of arrhythmia. AliveCor states that KardiaMobile "does not check for heart attack." If you feel chest pain, none of these devices is the thing you should be reaching for.
What a Lead Actually Is, and Why the Number Matters
A lead is not a wire. It is a viewpoint: the electrical difference measured between two points on the body, which gives you one angle on the heart's electrical activity. One lead is one camera at one angle. Twelve leads is a camera crew.
A single lead recording, which is what every smartwatch ECG and the base KardiaMobile produce, is Lead I, roughly a left-to-right view across the chest. It is genuinely good at answering whether the beat-to-beat timing is regular or irregular, which is the question that matters for atrial fibrillation. It is poor at localising anything, because you cannot triangulate a position from one angle.
The KardiaMobile 6L adds five more views by putting two electrodes under your fingers and one against your left knee or ankle, forming what AliveCor describes as an Einthoven Triangle, and records "leads I, II, III, aVL, aVR, and aVF." AliveCor received the first ever FDA clearance for a six lead personal ECG device on May 13, 2019. The company's own claim about what that buys you is worded carefully and worth quoting exactly: the device itself detects four rhythms, but with the six lead data "a doctor can detect over 30 conditions." The extra leads do not make your phone smarter. They make the recording you hand to a cardiologist more useful.
The Comparison
| Device | Leads | Price | Device-side FDA cleared determinations | Subscription needed | Hard requirements |
|---|---|---|---|---|---|
| Apple Watch ECG app | 1 | Included with the watch | Sinus rhythm, atrial fibrillation, low or high heart rate, inconclusive | No | Series 4 or later or any Ultra. Not SE, not Watch for Kids. Not for use under 22 |
| Samsung Galaxy Watch, Health Monitor | 1 | Included with the watch | Heart rhythm determination including atrial fibrillation | No | Galaxy Watch Active2 or newer, plus a Samsung phone on Android 12 or higher. Must be 22 or older |
| KardiaMobile | 1 | $79 | Normal sinus rhythm, atrial fibrillation, bradycardia, tachycardia | No | A compatible phone. No brand lock stated |
| KardiaMobile 6L | 6 | $114, list $129 | Normal sinus rhythm, atrial fibrillation, bradycardia, tachycardia | No | A compatible phone, plus contact with a knee or ankle for the third electrode |
| Withings BeamO | 1 | $249.95 | Single lead ECG trace. Interpretation comes from the Cardio Check-Up service | For interpretation, yes | Adults 22 and up for the ECG function |
Two things in that table surprise people. The first is that the six lead device does not detect more rhythms on its own than the $79 one. Both KardiaMobile models are cleared for the same four determinations. You are paying for a better recording, not a better verdict.
The second is the Samsung row. Samsung's ECG requires a Samsung phone running Android 12 or higher. Not an Android phone, a Samsung phone. If you own a Galaxy Watch and a Pixel, the ECG hardware on your wrist is inert. That is the single most common unpleasant surprise in this category, and it is a reason a $79 card can be the right purchase for someone who already owns a smartwatch.
What Each One Explicitly Cannot Do
The manufacturers are unusually clear about this, and reading their limitations side by side is more informative than reading their feature lists.
Apple lists what the ECG app does not detect, and the list is long: heart attacks, blood clots or strokes, high blood pressure, congestive heart failure, high cholesterol, and other forms of arrhythmia beyond AFib. Apple's guidance is direct: if you are not feeling well or are feeling any symptoms, talk to your doctor or seek immediate medical attention.
Samsung disclaims that information from the device "is not intended to diagnose, cure, mitigate, treat, or prevent disease or other conditions" and is "not intended to replace traditional methods of diagnosis or treatment." Samsung also rules out use by people with implanted electronic devices or near strong electromagnetic fields.
AliveCor states that both KardiaMobile models are "not tested or recommended for use with pacemakers and ICDs," that they do not check for heart attack, and that they do not replace regular checkups.
The pattern is consistent and it should shape how you use these things. They are rhythm instruments. They answer one question well. Every device here explicitly declines to be the thing you consult during a cardiac emergency.
The Age Floor Nobody Mentions
Apple, Samsung and Withings all restrict ECG to users 22 and over. Apple states the ECG app "is not intended for use by people under 22 years old." Samsung requires users to be at least 22. Withings' BeamO ECG is restricted to adults aged 22 and up.
That is not a legal quirk, it reflects how the algorithms were validated. But it has a practical consequence worth stating plainly: if you are a young adult with palpitations, which is a common enough reason to want one of these, the watch on your wrist may formally decline to help you. AliveCor's product pages do not state an equivalent age floor for KardiaMobile, which is another reason the standalone card is the more flexible household purchase.
Where the Subscriptions Hide
None of the five devices puts basic ECG behind a paywall. The paywall is around interpretation and around anything beyond the four core rhythms.
AliveCor sells KardiaCare at $99.99 a year and KardiaCare Plus at $199 a year, both HSA and FSA eligible, with the annual plan described as 40% cheaper than paying monthly. What you get is advanced determinations covering six common arrhythmias, trend insights across ECG readings, blood pressure and symptoms, and clinician reviews, with four board certified cardiologist reviews per year included at the KardiaCare tier. Neither KardiaMobile requires it.
Withings takes the same shape further. BeamO launched in the US on November 13, 2025 at $249.95 with FDA clearance covering ECG, digital stethoscope and contactless temperature, and it takes four readings in under a minute. But interpreting the ECG has always meant using Cardio Check-Up, where a cardiologist reviews the trace within 24 hours, and that sits behind Withings+. From October 1, 2026 the same subscription also gates StethO Sense, the new AI analysis of the heart and lung sounds BeamO records. Withings+ runs $9.95 a month or $99.50 a year.
So the real question when comparing a $79 card to a $249.95 handheld is not the sticker price. It is whether you intend to pay roughly $100 a year, indefinitely, for a human or an algorithm to read what your device records. Over three years that doubles the cost of the cheaper device and adds 120% to the more expensive one.
How to Choose
You already own an eligible watch. Use it first, for a month. An Apple Watch Series 4 or later, or any Ultra, gives you the same four-outcome answer as a $79 device, and Apple Watch adds passive irregular rhythm checks between your deliberate recordings, which is a genuine advantage a card cannot match. Only buy something else once you know what your watch is missing.
You own a Galaxy Watch but not a Samsung phone. Buy the $79 KardiaMobile. The ECG on your wrist will not work for you, and no software update is going to change that.
Your doctor asked you to capture an episode. Buy the KardiaMobile 6L. This is the one case where the extra five leads clearly earn their money, because the recording is going to be read by someone who can use them.
You want a general household health device. BeamO is the most versatile object here, combining ECG, digital stethoscope and thermometer, but budget for Withings+ because without it the ECG and sound features return recordings rather than answers.
You are worried about a symptom right now. None of these. Call a doctor.
Where Vora Fits
Two honest notes about what happens to this data afterwards, because it is the part buying guides never cover.
An ECG result is not a daily metric. It is an event: a 30 second recording with a classification attached, taken because something prompted you to take it. It does not belong in a trend line next to your sleep score, and treating it as one would be a category error. Vora reads from Apple Health and Health Connect rather than talking to devices directly, so the continuous context around an event, your resting heart rate drifting up over a fortnight, a run of poor sleep, a training block you did not recover from, is exactly the material we can work with. The recording itself stays where it belongs, in the app that made it and in front of a clinician.
That context is often the more useful half. A single AFib classification tells a doctor what happened once. Resting heart rate, HRV and sleep across the weeks around it tell a fuller story about what your body was doing at the time, and those are metrics Apple Health and Health Connect do define, which means they travel. Our integrations page lists what we read, and which wearable metrics actually sync to Apple Health covers why the sync path decides how useful a device turns out to be.
If you are shopping the wider at-home clinical category, blood pressure watches in 2026 is the neighbouring market where the accuracy claims are loudest and the validation thinnest, and the Huawei Watch D3 shows what an actual inflatable cuff on a wrist costs and requires.