Amazfit GTS 3 — Specs, Features & Review

Amazfit · GTS Series · Zepp OS · Launched October 2021

Amazfit GTS 3

The Amazfit GTS 3 is a slim, rectangular AMOLED smartwatch built around Zepp OS — offering an ultra-thin 8.8mm profile, a 1.75-inch 341 ppi display with 1,000-nit peak brightness, 12-day battery life, 5-satellite GPS, 150+ sports modes, and comprehensive health tracking at a weight of just 24.4 grams. The thinnest, lightest, sharpest-screened watch in the third-generation Amazfit lineup.

1.75" AMOLED · 341 ppi 8.8mm Thin · 24.4g 12-Day Battery 150+ Sports Modes 5-Satellite GPS Barometric Altimeter SpO₂ · Heart Rate · Stress VO2 Max Always-On Display Amazon Alexa 5 ATM Water Resistant Zepp OS

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1.75" AMOLED · 341 ppi

390×450 · 1,000 nits peak · 72.4% screen-to-body ratio

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12 Days (typical use)

6 days heavy use · 20hr GPS · 24-day battery saver

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24.4g · 8.8mm thin

Lightest in the GTS/GTR Gen 3 family

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150+ Sports Modes

8 auto-detect · GPS · GLONASS · Galileo · BDS · QZSS

GTS 3 (This Watch) — The Thin & Light One

✔Rectangular dial — wider, notification-friendly screen

✔8.8mm · 24.4g — thinnest & lightest of Gen 3

✔12-day battery (typical) · 20hr GPS

✔No speaker/mic · No music storage · Single-band GPS

GTR 3 Pro — The Premium Step-Up

✔Round dial — traditional watch look

✔Built-in speaker & mic — Bluetooth phone calls

✔2.3GB music storage — leave phone behind

✔12-day battery (typical) — same endurance, heavier build

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Key Features

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1.75" Ultra-HD AMOLED Display

The GTS 3's 390×450 AMOLED panel is the largest and sharpest in the Gen 3 Amazfit family, with a 341 ppi pixel density that delivers crisp text and vibrant colour across the full 72.4% screen-to-body ratio. The slightly curved glass screen blends seamlessly into the bezel-less design for an immersive look. Peak brightness hits 1,000 nits — visible in direct sunlight where many competitor screens wash out. Always-On Display mode provides a passive watch face at all times, and 100+ watch faces include 15 animated options and 12 user-editable layouts. You can even upload your own photo as a watch face background.

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12-Day Battery Life

Rated for 12 days of typical use from a 250mAh battery — a significant step up from the GTS 2's 7-day rating. In practice, expect 4–7 days depending on how actively you use the always-on display, GPS, and health monitoring. With all features in full use including AOD, real-world testing shows 4–5 days. Without AOD, 6–7 days is achievable. Battery saver mode stretches to 24 days by disabling most active monitoring. The 20-hour continuous GPS endurance is solid for multi-day hiking or running events. Charging from flat takes approximately 2 hours via the proprietary magnetic dock — there is no wireless charging.

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5-Satellite GPS System

The GTS 3 supports all five major satellite positioning constellations: GPS, GLONASS, Galileo, BDS (BeiDou), and QZSS. Multi-constellation support means faster position lock and more accurate route tracking, particularly in urban canyons and dense canopy environments where single-constellation devices struggle. A built-in barometric altimeter complements the GPS for accurate elevation data during hikes and climbs — measuring changes in air pressure to compute altitude independent of satellite signal quality. Combined, the GTS 3 delivers reliable outdoor navigation data for runners, hikers, and cyclists without requiring a phone connection.

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Comprehensive Health Tracking

The GTS 3 continuously monitors heart rate, blood oxygen saturation (SpO₂), stress levels, and breathing rate 24 hours a day. SpO₂ tracking is automatic rather than on-demand only — the watch samples blood oxygen throughout the day and during sleep. One-tap measurement takes 45 seconds and simultaneously reports heart rate, SpO₂, stress, and breaths per minute in a single reading. Women's health tracking includes menstrual cycle monitoring. Sleep tracking analyses sleep stages and provides a scored nightly report. The Zepp app aggregates all data into trend views and provides personalised health insights over time.

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150+ Sports Modes & Training Analytics

Over 150 built-in sports modes span outdoor running, cycling, swimming, rowing, skiing, hiking, rock climbing, martial arts, e-sports, and dozens more niche activities. Eight sports are auto-detected — the watch recognises your movement patterns and prompts you to start recording without manual activation: Outdoor Running, Treadmill, Walking, Indoor Walking, Outdoor Cycling, Pool Swimming, Rowing Machine, and Elliptical. Training analytics include VO2 Max, full recovery time estimation, training load (7-day aggregate), and training effect scoring — giving both beginners and experienced athletes actionable performance data after every session.

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Zepp OS & Smart Features

The GTS 3 runs Zepp OS — Amazfit's in-house operating system — with 60fps animations and a UI optimised for low power consumption. A physical crown on the right edge allows tactile navigation with haptic feedback from the linear motor. Amazon Alexa is built in for online voice commands; an offline assistant handles watch operations without internet. Smartphone notifications (calls, messages, apps) display on-screen, though the GTS 3 cannot answer calls or store music — it lacks a speaker and mic. Third-party mini apps are available through the Zepp app ecosystem, including Google Fit, Strava, and Relive workout data sync, plus weather, calendar, and camera remote control.

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Overview

Launched in October 2021, the Amazfit GTS 3 is the third generation of Amazfit's rectangular smartwatch line, sitting alongside the round-dial GTR 3 and GTR 3 Pro. The GTS 3's defining positioning within the Gen 3 family is its extreme lightness and thinness — at 24.4g and 8.8mm, it is meaningfully lighter and slimmer than the GTR 3 (32g) and GTR 3 Pro (34g), making it the recommended option for those who prioritise all-day wearability comfort and fashion-forward aesthetics over the premium speaker/mic features of the Pro model.

The GTS 3 competes in the mid-tier smartwatch bracket. It occupies an interesting position: for those who can accept Zepp OS's closed ecosystem limitations — no Google Pay, no app store in the traditional sense, no call answering — the GTS 3 delivers a display, health tracking suite, and battery life that flat-out embarrasses more expensive options from brands like Fitbit at similar price points. Where the Apple Watch SE and Samsung Galaxy Watch 4 offer richer smartwatch ecosystems, they do so with daily charging requirements and significantly heavier builds.

The honest trade-offs are worth stating upfront: the GTS 3 cannot answer phone calls, cannot store or play music, and runs a proprietary OS with a limited app ecosystem. These are deliberate product design choices that preserve battery life and the slim form factor. If you need those features, the GTR 3 Pro is the step-up. If you can work without them, the GTS 3 offers an outstanding health and fitness tracking experience in the most wearable form factor in its class.

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Battery Life

12 days

Typical use (rated)

6 days

Heavy use (rated)

20 hrs

Continuous GPS

24 days

Battery saver mode

Real-world battery life falls between the 6-day heavy use and 12-day typical use ratings depending on your specific usage patterns. The biggest battery drain factor is the always-on display — enabling AOD in real-world testing typically yields 4–5 days. Turning AOD off and using raise-to-wake instead can stretch this to 6–7 days with active health monitoring and 30–60 minutes of daily GPS exercise. The 250mAh cell charges fully in approximately 2 hours via the magnetic dock.

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Health & Fitness Features

❤️ 24/7 Heart Rate 🩸 SpO₂ (Auto) 😤 Stress Monitoring 💤 Sleep Tracking + Stages 🫁 Breathing Rate 🔬 VO2 Max 📈 Training Load ⏱️ Recovery Time 🚺 Menstrual Cycle 📊 PAI Health Score

✔24-hour continuous heart rate monitoring

✔Automatic SpO₂ (blood oxygen) monitoring

✔Stress level monitoring (heart rate variability)

✔Breathing rate monitoring

✔Sleep tracking — stages, duration, score

✔VO2 Max estimation

✔Training load (7-day aggregate)

✔Full recovery time estimation

✔Training effect scoring

✔PAI Health Assessment System

✔Step counter · Distance · Calories burned

✔Menstrual cycle tracking (women's health)

✔One-tap 45-second full health measurement

✔Sedentary reminders · Inactivity alerts

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Full Technical Specifications

Display
Display Type	AMOLED
Size	1.75 inches
Resolution	390 × 450 pixels
Pixel Density	341 ppi
Peak Brightness	1,000 nits
Screen-to-Body Ratio	72.4%
Always-On Display	Yes — matching AOD for all 100+ watch faces
Glass	Curved tempered glass
Design & Build
Shape	Rectangular
Dimensions	42.4 × 36 × 8.8 mm
Weight (no strap)	24.4g
Case Material	Aluminium alloy
Strap Width	20mm — standard swappable
Colours	Graphite Black · Terra Rosa · Ivory White
Water Resistance	5 ATM (50 metres)
Navigation
Controls	Touchscreen + physical crown (right side) with haptic feedback
Crown Function	Scroll navigation (rotation) + single press select
Battery
Capacity	250 mAh
Typical Use	Up to 12 days
Heavy Use	Up to 6 days
GPS Continuous	Up to 20 hours
Battery Saver Mode	Up to 24 days
Charging Time	Approx. 2 hours (magnetic dock)
Charging Type	Proprietary magnetic — no wireless charging
GPS & Sensors
Satellite Systems	GPS · GLONASS · Galileo · BDS · QZSS (5 constellations)
GPS Band	Single-band (L1)
Sensors	Acceleration · Gyroscope · Geomagnetic · Barometric altimeter · Ambient light · PPG heart rate · SpO₂
Sports & Fitness
Sports Modes	150+
Auto-Detection	8 sports: Outdoor Running, Treadmill, Walking, Indoor Walking, Outdoor Cycling, Pool Swimming, Rowing Machine, Elliptical
Swim Tracking	Yes — heart rate during swimming
Connectivity & Smart Features
Bluetooth	Bluetooth 5.0 BLE
Wi-Fi	No
Voice Assistant	Amazon Alexa (online) + offline voice assistant
Phone Calls	No — no speaker or microphone
Music Storage	No
Notifications	Yes — calls, messages, app alerts (display only, no reply)
Third-Party Apps	Limited Zepp OS mini app ecosystem; Strava, Google Fit, Relive sync
Watch Faces	100+ including 15 animated · 12 editable · custom photo upload
Compatibility
Android	Android 7.0 and above
iOS	iOS 12.0 and above
App	Zepp (by Zepp Health / Huami)
NFC / Payments	No

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Verdict

✅ What We Like

+Extraordinary thinness and lightness — 8.8mm and 24.4g is genuinely impressive engineering; the GTS 3 disappears on the wrist in a way no Galaxy Watch or Apple Watch can claim

+Best-in-class display for the price bracket — 341 ppi, 1,000 nits, 72.4% screen-to-body with matching AOD for every watch face is a combination that the Apple Watch cannot match on screen-to-body ratio

+Week-plus battery with competitive usage — while not matching Garmin's multi-week endurance, 12 days rated (4–7 days real-world) vastly outperforms the daily-charge smartwatch category

+Rich health tracking suite — automatic SpO₂, VO2 Max, training load, recovery time, sleep stages, and menstrual tracking represents a genuinely comprehensive health package

+5-satellite GPS + barometric altimeter — for a light recreational watch, having all five satellite constellations plus a proper altimeter is above what the competition offers at this weight class

⚠️ Things to Know

−No speaker, no mic, no call answering — the GTS 3 cannot answer or make phone calls; it shows call notifications on screen only. Step up to the GTR 3 Pro if Bluetooth calling is important to you

−No music storage — unlike the GTR 3 Pro, the GTS 3 has no onboard storage for music; you'll need your phone nearby for audio during workouts

−Closed ecosystem — Zepp OS has a limited third-party app selection; no Spotify, no Google Pay, no Google Maps. The watch does what it does very well, but you are within Amazfit's walled garden

−Single-band GPS only — the GTS 3 uses single-band L1 GPS; for high-precision urban running or complex terrain, dual-band (added in the GTS 4) offers meaningfully better accuracy

−No notification replies — the watch can display notifications but cannot send quick replies; a limitation of the hardware's lack of microphone

Bottom Line

The Amazfit GTS 3 is the best thin-and-light health smartwatch for buyers who don't need Bluetooth calls or music storage. Its 8.8mm / 24.4g engineering, 341 ppi AMOLED display with 1,000-nit brightness, genuine 5-satellite GPS with altimeter, and comprehensive health suite including automatic SpO₂, VO2 Max, and sleep staging represent a feature package that competes well above its weight class. The closed Zepp OS ecosystem and absent speaker/mic are real trade-offs — but for an always-on health and fitness companion that you'll barely notice on your wrist, the GTS 3 remains one of the most compelling rectangular smartwatches ever made at this form factor. Upgrade to the GTS 4 if you want dual-band GPS and Bluetooth calling; stick with the GTS 3 if battery life and lightness are your priorities.