A hybrid analog watch with a regulator-cleared ECG (per Withings) and a ~30-day battery — strong on health-screening features, competent rather than class-leading as a dedicated HRV tracker.Best for a discreet hybrid watch with a regulator-cleared ECG (per Withings) and no subscription.
The Withings ScanWatch 2 is the clinical-health pick here — a hybrid analog watch with a regulator-cleared single-lead ECG, SpO2, temperature and sleep-apnea detection, a roughly 30-day battery and no subscription. As a pure HRV tracker it is competent rather than class-leading.
How we tested: Evidence-based assessment — scored from manufacturer specifications, independent 2026 reviews and published validation literature. Not hands-on tested by ONDA.
Overnight optical HRV plus an on-demand single-lead ECG — solid, though the continuous signal is optical, not electrical.
Sensor and signal quality
8.0
Optical PPG paired with a regulator-cleared single-lead ECG, SpO2 and a temperature sensor.
Sleep tracking accuracy
7.0
Competent sleep tracking with a sleep-quality score and breathing-disturbance (apnea) detection.
Data access and export
7.0
The Withings Health Mate app, with reasonable export and a developer API.
Wearability and battery
8.5
A roughly 30-day battery in a discreet hybrid analog watch — the easiest device here to simply wear and forget.
App and software experience
7.0
Health Mate is clean and clear, if less recovery-focused than Oura or Whoop.
Value
7.5
A one-time purchase around 350 USD, no subscription, with a regulator-cleared ECG (per Withings).
Pros
+Regulator-cleared single-lead ECG on the wrist
+A discreet hybrid analog design with a ~30-day battery
+No subscription — clinical features unlocked at purchase
+Sleep-apnea and SpO2 screening built in
Cons
−Continuous HRV is optical, not electrical — not reference-grade
−Less recovery-focused than Oura or Whoop
−A small dial and no full touchscreen
−HRV is a secondary metric, not the headline
Price: $350 one-time; no subscription (as of 2026-05-16)
Where it leads
The Withings ScanWatch 2 is the clinical-health pick of this comparison. It looks like an ordinary analog watch, but it carries a regulator-cleared single-lead ECG, SpO2, a temperature sensor and breathing-disturbance detection — and it runs for roughly a month on a charge. It is the easiest device here to simply wear and forget, and there is no subscription: the clinical features are unlocked at purchase.
What are the downsides of Withings ScanWatch 2?
For dedicated HRV work it is competent rather than class-leading. The ECG is an on-demand spot reading, not a continuous protocol, so the all-night HRV signal is still optical — fine for trends, less precise than a chest-strap ECG at rest. It is also less recovery-focused than Oura or Whoop: HRV is one health metric among many here, not the headline.
Who should buy Withings ScanWatch 2?
Choose the Withings ScanWatch 2 if you want a discreet, long-lasting watch with genuine clinical screening — ECG, SpO2, apnea — and no subscription, and you treat HRV as one signal among several. If overnight HRV and recovery are the whole point, a dedicated ring or band will track them more closely.
Background reading
The science behind why HRV is the signal worth tracking — and how the body produces it.
Does the Withings ScanWatch 2 need a subscription?
No — it is $350 one-time with no subscription. It is a hybrid analog watch with a regulator-cleared ECG and AFib detection (per Withings), plus SpO2 and body temperature, and multi-week battery.
Is the Withings ScanWatch 2 good for HRV?
It tracks overnight HRV and sleep competently for a hybrid watch and adds a regulator-cleared ECG with AFib screening (per Withings). ONDA scores it 7.4/10.
How long does the Withings ScanWatch 2 battery last?
About 30 days per charge — far longer than a full smartwatch, because it is a hybrid analog design with physical hands. That makes continuous overnight HRV and sleep tracking easy without nightly charging.
