AirPods Pro 3 heart rate accuracy rivals Apple Watch in lab tests

At a glance:

• AirPods Pro 3 achieved 1.67% heart rate error in CNET Labs testing, second only to Apple Watch Series 11 (0.98% error).
• A peer-reviewed PLOS Digital Health study validated the findings with 40 adults and 16,735 paired measurements.
• At $250, AirPods Pro 3 offer heart rate tracking at $150 less than the $400 Apple Watch Series 11.

What happened

Apple's AirPods Pro 3 have emerged as a surprising contender in heart rate accuracy, according to testing by CNET Labs. The earbuds' photoplethysmography (PPG) sensor achieved an average error rate of 1.67% when compared to a medical-grade Polar H10 chest strap, making them the second-most accurate consumer heart rate device tested by the publication. Only the Apple Watch Series 11 outperformed them, with an error rate of 0.98%. These results suggest that Apple's latest earbuds could serve as a viable alternative for users seeking heart rate data during workouts without investing in a smartwatch.

The testing protocol followed a rigorous four-lap track method, aligning with standards used in exercise physiology labs to validate optical heart rate sensors. CNET Labs' methodology has historically provided reliable benchmarks, though the publication noted limitations in sample size for the AirPods Pro 3 tests, completing only two full runs. Despite this, the results place the AirPods ahead of all other smartwatches and fitness trackers tested by the lab, including devices from Samsung, Garmin, and Fitbit.

How it works

The AirPods Pro 3's PPG sensor operates by emitting infrared light at 256 times per second to detect blood volume changes in the ear canal. Apple claims the sensor was trained on over 50 million hours of data from the Apple Health Study, enabling it to adapt to individual physiological variations. The sensor's compact design represents Apple's smallest heart rate sensor to date, leveraging the ear canal's stable optical environment—less susceptible to ambient light and motion interference than wrist-based sensors.

This approach builds on years of research into ear-based biometric sensing, which has long been explored in academic settings. The ear's vasculature sits closer to the skin surface than the wrist, allowing for more precise readings with smaller hardware. However, the trade-off is that AirPods lack the broader health monitoring capabilities of smartwatches, such as blood oxygen measurement, ECG, or skin temperature tracking.

Independent validation

A peer-reviewed study published in PLOS Digital Health in April 2026 further corroborated the AirPods Pro 3's accuracy. Researchers tested 40 adults across 16,735 paired heart rate measurements and found an average deviation of 2.02% from a reference device. The study emphasized that the ear canal's optical stability reduces motion artifacts during exercise, a common issue with wrist-worn devices.

However, the research highlighted a limitation: epoch-to-epoch variability increases at higher exercise intensities. While the overall average remained close to the reference, individual readings became less consistent during rapid heart rate changes, such as interval training. This aligns with known challenges in optical heart rate sensing, where motion and blood flow dynamics can affect precision.

Market implications

At $250, the AirPods Pro 3 undercut the $400 Apple Watch Series 11, offering a cost-effective option for users prioritizing heart rate tracking. Apple does not market the AirPods as medical devices, and the heart rate feature lacks FDA clearance for clinical use—unlike the Apple Watch's ECG and irregular rhythm notification capabilities. The AirPods measure heart rate exclusively, omitting arrhythmia detection, blood oxygen, or other advanced metrics.

For competitors, the results raise the bar significantly. Samsung, Google, and Xiaomi currently sell earbuds without heart rate monitoring approaching Apple's demonstrated accuracy. While PPG technology is well-understood, Apple's advantage stems from its massive training dataset and high sampling rate rather than proprietary hardware innovations. This positions the company to lead in multi-sensor health data aggregation, as the Apple Health app already integrates data from multiple sources.

Broader trends in health wearables

The AirPods Pro 3 reflect a broader shift toward diversified health wearable form factors. Oura's Ring 5 monitors heart rate, temperature, and respiratory rate from the finger, while Whoop focuses on recovery metrics via a screenless wristband. Google's Fitbit Air, priced at $99, adds AI-driven health coaching to the mix. These devices underscore a growing emphasis on unobtrusive, specialized health tracking beyond traditional smartwatches.

Apple's dual-device strategy—offering heart rate sensing in both earbuds and watches—could enable cross-referencing data to improve accuracy. Though real-time sensor fusion remains unannounced, the company's machine learning research suggests potential for combining inputs from multiple body locations. This approach may become critical as health wearables evolve to meet diverse user needs.

Competitor landscape and future outlook

Samsung, Google, and Xiaomi have yet to match Apple's heart rate accuracy in earbuds, despite offering competing audio products. The PPG technology itself is not novel, but Apple's integration of high-frequency sampling and extensive training data gives it an edge. For users focused solely on heart rate during exercise, the AirPods Pro 3's performance narrows the gap with the Apple Watch, though the latter remains superior for comprehensive health monitoring.

The success of ear-based sensors could spur innovation in other body-worn devices, such as smart rings or patches. However, the AirPods' limitations—lack of clinical features and reduced reliability during intense activity—mean they are unlikely to fully replace smartwatches in the near term. Instead, they represent a compelling middle ground for fitness enthusiasts seeking affordability and convenience.

Conclusion

The AirPods Pro 3's heart rate accuracy marks a significant milestone in wearable technology, blending audio functionality with health tracking in a mass-market product. While not a substitute for medical-grade devices or the full suite of Apple Watch features, their performance validates the ear canal as a viable biometric sensing location. As competitors race to close the gap, Apple's dual-device ecosystem may set the stage for next-generation health monitoring strategies.