Review · 6 min read
Amazfit GTR 4: Sleep Tracking Data and Specifications
Amazfit GTR 4 review built from Amazfit's published product information. AMOLED smartwatch, 34.1g, 14-day typical battery, BioTracker 4.0 PPG sensor, dual-band GPS, 5 ATM. No peer-reviewed PSG validation specific to the GTR 4 has been published.
Summary of Findings
Evidence summary: Amazfit GTR 4
No peer-reviewed PSG validation studies for the Amazfit GTR 4 are in the CircaTest corpus. This is an honest null result. CircaTest does not substitute manufacturer white papers, influencer reviews, or benchmarks from earlier generations of the same product line. When peer-reviewed validation appears, it will be added here automatically.
How CircaTest evaluates studies →Data Sources and Methodology
This review compiles data from Amazfit's official GTR 4 product page (us.amazfit.com/products/amazfit-gtr-4, verified April 6, 2026). No first-person testing was conducted.
Important caveat upfront: no peer-reviewed PSG validation specific to the Amazfit GTR 4 has been published. Amazfit has historically had less independent validation than Garmin, Polar, or Fitbit; the GTR 4 is no exception.
Sensor Suite
Per Amazfit's published product information:
- BioTracker 4.0 PPG biometric sensor (Amazfit's flagship optical heart rate sensor)
- Accelerometer + gyroscope + geomagnetic sensor
- Barometric altimeter + ambient light sensor
- Dual-band GPS with 6 satellite positioning systems
- Blood oxygen (SpO2) derived from PPG
No skin temperature sensor, no ECG. The GTR 4 occupies the same general feature category as the Garmin Venu 3 and Polar Vantage V3 but at a substantially lower price.
Sleep Tracking Features
Amazfit describes the GTR 4 as offering sleep stage tracking (light, deep, REM), a sleep score, sleep-in and wake-up time detection, respiratory rate monitoring during sleep, and blood oxygen saturation tracking during sleep. The Zepp Health app combines these into an overall “breathing quality” score during sleep. No peer-reviewed validation specific to the GTR 4's sleep staging exists.
Hardware
- Weight: 34.1 grams without strap; approximately 46 grams with the leather wristband.
- Display: 1.43 inch AMOLED touchscreen at 466 x 466 resolution.
- Battery: 475 mAh, up to 14 days typical usage, up to 50 days in basic watch mode. 1 hour 45 minutes to fully charge.
- Water resistance: 5 ATM (50 meters).
- Material: stainless steel bezel with polymer case.
Cost vs Features Trade-Off
At a typical $200 retail price, the GTR 4 sits between the Xiaomi Smart Band 9 budget tier and the $400+ Garmin / Polar / Apple flagships. The trade-off is that you get a near-flagship feature set (AMOLED, dual-band GPS, 14-day battery, sleep stages) for half the price of comparable Garmin and Polar watches, but with less independent validation, a less mature companion app ecosystem (Zepp Health), and no temperature or ECG sensors.
Who It Is For (Based on the Data)
- Budget-conscious users who want a full-featured AMOLED smartwatch without paying flagship prices
- Users who prioritize battery life (14 days typical, 50 days basic mode)
- Users who do not need temperature, ECG, or peer-reviewed validation
- Users comfortable with the Zepp Health app ecosystem
The device's data profile is less aligned with users who require peer-reviewed PSG validation for the specific model, users who depend on Apple Health integration (Zepp Health does not export to Apple Health), or users who need clinical-grade health features.
Products Mentioned
Budget AMOLED smartwatch. 34.1g, 14-day battery, BioTracker 4.0 PPG, dual-band GPS, 5 ATM. No peer-reviewed PSG validation specific to the GTR 4.