Looking for an ECG smartwatch that records a real electrocardiogram instead of just estimating your heart rate? REXQU builds four watches with on-wrist ECG, from a boardroom-ready dress watch to a screenless band that disappears under a cuff. This guide compares all four so you can pick the one that matches how you actually want to wear it.
What an On-Wrist ECG Actually Measures
An electrocardiogram records the electrical signal your heart generates with every beat, which is why it can show rhythm patterns a simple optical heart-rate sensor never catches. Rest a finger on the watch’s sensor for about 30 seconds and the app plots a waveform, alongside a rhythm summary you can review later or bring to your doctor.
It’s the same underlying principle used in clinic ECG machines, just condensed into a single-lead reading from your wrist instead of the multi-lead setup a hospital uses. You can read more about how electrocardiography works on Wikipedia. Clinical ECGs use multiple electrodes placed around the chest and limbs to capture the heart’s electrical activity from several angles at once, while a wrist watch simplifies that down to one lead — enough to catch rhythm irregularities worth flagging, even if it can’t replace the full diagnostic picture a hospital machine builds.
REXQU ECG Smartwatch Comparison
| Model | Price | Display | Battery | Standout Feature |
|---|---|---|---|---|
| REXQU Infinity Pro | $169.97 | 1.56″ round AMOLED, 480×480 | Multi-day (440mAh) | Zinc-alloy dress-watch case with ECG rhythm summaries, SOS and an LED flashlight |
| REXQU CardioSense | $159.97 | 2.01″ AMOLED | 5–7 days | Largest ECG display in the lineup, plus blood pressure and IP67 protection |
| REXQU PulseBand | $139.97 | Screenless (G BAND app) | 25–30 days | ECG sensor built into a screenless band, with HRV and overnight Lorenz scatter-plot analysis |
| REXQU HealthWave | $139.97 | 2.04″ AMOLED | Up to 4 days | Lowest-priced ECG option, with continuous heart-rate tracking alongside it |
Every model links back to the full ECG smartwatches shop page, where you can compare colors and current pricing directly.
Which Model Should You Wear?
If you want something that reads as a classic watch rather than a gadget, the Infinity Pro’s zinc-alloy round case hides a serious ECG engine — including HRV and QT indicators tracked over time — behind a dial that looks at home in a boardroom. It also throws in an SOS button and a genuine LED flashlight, which is a strange but genuinely useful pairing.
If you want the biggest, easiest-to-read display alongside your ECG traces, the CardioSense pairs a 2.01-inch screen with blood pressure tracking and a featherweight 40g body, plus IP67 water resistance for daily wear. It’s built with family sharing in mind, so someone checking in on a parent’s numbers can do it from the companion app.
If you’d rather not wear a screen at all, the PulseBand tucks a dedicated ECG sensor into a screenless band, then hands you a deeper heart-rate variability breakdown — including 27 types of overnight Lorenz scatter-plot views — in the G BAND app. It’s the pick for anyone who finds a lit-up display distracting, especially overnight.
If price is the deciding factor, the HealthWave delivers the same 30-second ECG capture as the pricier models, just without the extra sensors like blood pressure or stress tracking layered on top.
Battery Life and Everyday Wear
Battery life is where these four watches diverge the most, and it’s worth matching to how you actually live. The screenless PulseBand runs 25–30 days per charge because it has no display drawing power between readings, making it the obvious choice if you travel often or simply forget to charge things. The CardioSense and Infinity Pro both land in the multi-day range, comfortable for a normal week without a mid-week top-up. The HealthWave’s up-to-4-day battery is the shortest of the four, a fair tradeoff for its lower price, but worth factoring in if you dislike charging watches more than once or twice a week.
Recording an ECG Correctly
A clean ECG trace depends on a few basics. Sit still and rest your arm on a table rather than recording while walking or talking, since movement introduces noise into the waveform. Keep the recording finger relaxed on the sensor for the full 30 seconds rather than lifting it early. If a trace looks noisy or incomplete, retake it once before assuming something’s wrong — a shaky first attempt is common and rarely means anything by itself.
What These Watches Can and Can’t Tell You
Every REXQU model with ECG is designed for awareness and conversation with your physician, not for diagnosis. A single-lead wrist ECG can flag an irregular rhythm pattern worth mentioning at your next appointment, but it isn’t a substitute for a clinical 12-lead ECG or a cardiologist’s read of your results.
Independent research into smartwatch AFib detection backs up that framing — the technology is a useful early signal, not a diagnostic tool on its own, which is why every trace these watches record is meant to be shared with, not interpreted instead of, your doctor. The same goes for the extra wellness estimates some models offer, like glucose trends or body composition — treat those as patterns to discuss at your next visit, never as a standalone reading to act on.
Buying for a Parent or Partner
An ECG smartwatch is a common gift for a parent who’s had a heart scare, or a partner who keeps putting off a cardiology follow-up. The CardioSense’s large, high-contrast display and family-sharing setup make it easy for someone checking in remotely to see that readings are being taken regularly, while the Infinity Pro’s classic dial suits someone who’d never wear anything that looks like a fitness gadget.
Frequently Asked Questions
How long does an ECG recording take?
About 30 seconds on the Infinity Pro, CardioSense and HealthWave, with the PulseBand’s on-band sensor working the same way through the G BAND app.
Can it detect atrial fibrillation?
These watches record a rhythm trace and flag patterns worth a closer look, but any suspected AFib reading should be confirmed by a doctor rather than acted on from the app alone.
Do I need a subscription to use the ECG feature?
No. Every model in this guide records and stores ECG traces in its free companion app with no ongoing subscription.
Which model has the best battery life?
The screenless PulseBand leads by a wide margin at 25–30 days per charge, since it has no display drawing power between readings.
Is one ECG smartwatch more accurate than another?
All four use a comparable single-lead sensor and the same underlying electrocardiography principle, so the meaningful differences between them come down to display, battery and extra sensors rather than ECG accuracy itself.
Can I record an ECG during a workout?
No — sit still with your arm resting on a table for the full recording. Movement during the 30-second window will add noise to the trace on any of these models.
The Bottom Line
All four REXQU watches record a genuine on-wrist ECG — the real difference is how you want to wear it. Choose the Infinity Pro for a dress-watch look, the CardioSense for the biggest display and blood pressure tracking, the PulseBand if you want no screen at all, or the HealthWave if price comes first. Compare colors and current pricing on the full ECG smartwatches shop page.