The Best Smartwatch for Heart Health Monitoring, Tested

The uncomfortable answer is that the best smartwatch for heart health monitoring, based on the external accuracy data used for this comparison, is not simply the watch with the lowest heart-rate error. The Apple Watch Series 11 is the clear leader in CNET’s 2026 wrist-versus-chest-strap running test, averaging 0.98% error, or about 1.4 beats per minute, against a Polar H10 chest strap. But a heart-health purchase also depends on which features have been cleared for ECG, irregular-rhythm or AFib notification, and hypertension alerts — and those differences are large enough to change the recommendation. [1]

A note on the word “tested”: the accuracy figures below are external test results, not NestGrid lab results. CNET ran more than 30 miles total, using one tester and three 1-mile runs per watch, so the numbers are useful head-to-head evidence, not a universal guarantee for every wrist, workout, firmware version, or medical condition. [1]

The accuracy winner is clear; the heart-health winner needs a second filter

If this were only a workout heart-rate article, the Apple Watch Series 11 would make the decision almost boring. A sub-1% average error against a Polar H10 chest strap is excellent for a wrist device, and the rest of the field sits far enough behind that the ranking matters: Garmin Venu 4 at 3.89%, Pixel Watch 4 at 5.6%, Galaxy Watch 8 at 6.6%, and Amazfit Bip 6 at 7%. All five stayed under 8% error in CNET’s test, which is better than many shoppers probably expect from optical sensors on moving wrists. [1]

But “heart health” is not the same as “my running graph looks smooth.” A watch can track pulse well during a run and still lack the cleared feature a buyer thinks they are getting. ECG, passive irregular-rhythm notification, AFib-related alerts, blood-pressure tracking, and hypertension notification are different claims. They do not become interchangeable because they live in the same Health app tab.

That distinction is why the Apple Watch Series 11 gets the most defensible overall recommendation here. It combines the best external heart-rate result in the current five-watch field with the strongest cleared heart-feature profile in the supplied materials. For an iPhone user who wants a watch that may help prompt follow-up for rhythm concerns or possible hypertension risk, that pairing is the cleanest buy. [1][2]

The caveat is not small: no watch on this list diagnoses hypertension, rules out AFib, or replaces a medical ECG. Apple’s advantage is that its feature set is better aligned with the heart-health use case many buyers actually have. That is different from saying the watch is a doctor on the wrist.

Samsung’s blood-pressure feature is the easiest one to misunderstand

The Galaxy Watch 8 deserves more caution than its 6.6% heart-rate error alone suggests. For Samsung phone owners, it may be the most natural Android pick: it belongs in the Galaxy ecosystem, supports FDA-cleared irregular heart rhythm notification, and now has U.S. blood-pressure monitoring in Samsung Health. [1][4][5]

The trap is assuming that blood-pressure tracking equals an FDA-cleared hypertension notification feature. Samsung’s U.S. blood-pressure monitoring announcement says users need recalibration with an upper-arm cuff every 28 days; the same announcement does not make the BP feature the same kind of cleared claim as Apple’s hypertension notifications. [5]

That does not make the Galaxy Watch 8 a bad heart-health watch. It makes it a watch whose feature labels matter. If you already prefer Samsung hardware, also want smart-home convenience, and are comparing models inside that ecosystem, our Galaxy Watch 8 smart-home guide and broader Galaxy Watch model guide can help with the nonmedical part of the purchase.

Garmin, Pixel, and Amazfit: three different kinds of “good enough”

Garmin Venu 4 is the easiest runner-up to respect. Its 3.89% average error put it second in CNET’s test, and the 1-second sampling detail matters for people who care about exercise traces rather than occasional wellness snapshots. Garmin’s ECG App clearance history also gives it more heart-feature substance than a generic fitness watch. [1][3]

What Garmin does not get is the same hypertension-notification argument as Apple. If your purchase is mostly about training, recovery, and having ECG available on a supported Garmin model, the Venu 4 belongs high on the list. If your main worry is possible high blood pressure going unnoticed, the Apple-Samsung-Garmin comparison should not be reduced to heart-rate accuracy alone.

Pixel Watch 4 lands in the middle: 5.6% average error in the current CNET test, which is usable for many everyday heart-rate trends, but not close to Apple’s result. The bigger issue is not to carry evidence across models. The peer-reviewed validation data cited above covers Pixel Watch 2, not Pixel Watch 4, so it should not be used as if it directly validates Google’s 2026 flagship. [1][6]

Amazfit Bip 6 is the budget outlier. A 7% average error is not automatically disqualifying for casual trends, and it stayed within the broad under-8% cluster in the CNET field. But the missed peak spikes matter, and the cited sources do not establish the cleared ECG, rhythm, or hypertension feature set that would make it a serious heart-health-monitoring recommendation. [1]

Why 1% versus 7% does not settle the medical question

Wrist optical heart-rate sensors have become good enough that dismissing them as toys is no longer fair. In a 2026 JMIR Formative Research validation of 10 commercial wearables in 45 adults, the Fitbit Charge 6 and Pixel Watch 2 were the only devices that met both the study’s concordance threshold and the ANSI-style cardiac-monitor boundary of ±10% mean absolute percentage error or ±5 bpm. The Fitbit Charge 6 posted 4.5 bpm mean absolute error and 5.5% MAPE; Pixel Watch 2 posted 4.9 bpm MAE and 6.7% MAPE. [6]

That is encouraging, but it is not permission to blur generations. Pixel Watch 2 performance in a controlled validation study does not directly prove Pixel Watch 4 performance, just as Fitbit Charge 6 data does not rank the five watches in CNET’s 2026 field. The more useful lesson is broader: some wrist wearables can be credible against ECG-style references, while others still drift enough to matter. In the same JMIR study, Inspire 3, Polar Ignite 3, Polar Pacer, and Oura Gen 3 showed mean absolute errors in the 9-to-14 bpm range. [6]

The weak spot is usually not a calm walk at a steady pulse. It is the messy stuff: peak intensity, fast changes, poor fit, movement, cold skin, sweat, and the few seconds when your heart rate is rising faster than the watch can confidently follow. CNET saw lag in Zone 5 efforts above roughly 160 bpm, and a 2024 Scientific Reports study on remote exercise-capacity assessment found peak-exercise outlier rates of about 7% for Garmin and about 12% for Fitbit in the devices studied. [1][7]

There is also a fairness problem that the industry has not fully put to bed. A 2022 American College of Cardiology summary of a systematic review covering 10 studies and 469 participants reported that smartwatch heart data accuracy may vary by skin tone. The evidence is directional rather than final, but it is enough to make sweeping “works for everyone” claims irresponsible. [8]

What to buy, depending on the heart-health job

• Best overall heart-health pick: Apple Watch Series 11. Choose it if you use an iPhone and want the best tested heart-rate accuracy in this group plus the strongest cleared rhythm-and-hypertension feature story. [1][2]
• Best fitness-first alternative: Garmin Venu 4. Choose it if exercise heart-rate accuracy, training use, and Garmin’s ECG-supported watch ecosystem matter more than hypertension notifications. [1][3]
• Best Samsung/Android ecosystem pick with caveats: Galaxy Watch 8. Choose it if you are committed to Samsung and understand the difference between FDA-cleared IHRN and cuff-calibrated BP tracking. [4][5]
• Reasonable Android generalist: Pixel Watch 4. Choose it for everyday smartwatch use and heart-rate trends, not because older Pixel Watch validation automatically proves the current model’s medical-grade performance. [1][6]
• Budget heart-rate tracker, not the serious heart-health pick: Amazfit Bip 6. Choose it only if cost is the main constraint and you are comfortable treating the data as wellness context. [1]

Prices and promotions move quickly in this category, especially as older watches stay on shelves beside newer flagships. If you are buying for yourself or a family member, it is worth checking current wellness-tech deals before choosing a model, but the discount should not override the heart feature you actually need.

For caregivers, the heart-monitoring question often sits beside fall detection, medication routines, and emergency contact setup. If that is the real use case, pair this watch comparison with a broader look at smart-home and wearable fall-detection tools for older adults rather than expecting one watch feature to cover the whole safety plan.

Use the watch as a prompt, not a verdict

The safest way to use any of these watches is as a monitoring aid: a way to notice patterns, capture symptoms in time, and decide when to follow up. IU Health’s clinician guidance makes the same practical point: smartwatches can help people spot possible heart issues, but they do not replace medical evaluation. [9]

If a watch flags an irregular rhythm, repeated high readings, or a pattern that matches symptoms such as chest pain, fainting, unusual shortness of breath, or palpitations, the next step is not another watch comparison. It is a clinician, a validated cuff, a medical ECG, or emergency care when symptoms are urgent.

References

1. I Ran 30 Miles With 5 Smartwatches. Here's the One You Can Actually Trust — CNET
2. Apple debuts Apple Watch Series 11, featuring groundbreaking health insights — Apple Newsroom, September 9, 2025
3. Garmin expands ECG App to additional smartwatches, including its flagship epix Pro and fēnix 7 Pro series — Garmin
4. Samsung Announces FDA-Cleared Irregular Heart Rhythm Notification for Galaxy Watch — Samsung Newsroom
5. Samsung's Blood Pressure Monitoring Feature Now Available to U.S. Users in Samsung Health — Samsung Newsroom, March 31, 2026
6. Accuracy of Optical Heart Rate Measurements for 10 Commercial Wearables in Different Climate Conditions and Activities — JMIR Formative Research, 2026
7. Accuracy of smartwatches for the remote assessment of exercise capacity — Scientific Reports, 2024
8. How Accurate Is Smartwatch Heart Data? It Depends on Your Skin Tone — American College of Cardiology, March 23, 2022
9. Should I get a smart watch if I have heart issues? — IU Health