Xiaomi Watch S4 – Full Specifications

Dimensions & Weight

• Size: 47.3mm × 47.3mm × 12.0mm (excluding strap)

• Weight: ~44.5g (without strap)

Design & Build

• Frame: Aluminum alloy (PVD-coated stainless steel-like finish)

• Strap Options:

  • Black/Silver: Fluororubber (140–210mm adjustable)

  • Rainbow: Fluororubber + Nylon (135–210mm adjustable)

• Interchangeable Bezels: Optional (Carbon, Ceramic, Stainless Steel, etc.)

Display

• Type: 1.43-inch AMOLED

• Resolution: 466 × 466 pixels (326 PPI)

• Brightness:

  • HBM (High Brightness Mode): 1500 nits

  • Peak Brightness: 2200 nits

• Refresh Rate: 60Hz (varies by interface)

• Moisture-Resistant Touch: Prevents accidental water-triggered inputs

Sensors

• Heart rate (with SpO2)
• Accelerometer
• Gyroscope
• Ambient light sensor
• Electronic compass
• Barometer
• Hall sensor

Satellite Positioning (GNSS)

• Dual-Frequency (L1 + L5): GPS, Galileo, GLONASS, BeiDou, QZSS

Battery & Charging

• Capacity: 486mAh
• Battery Life: Up to 15 days (typical usage)
• Fast Charging: 5 mins → 2 days of use
• Charging Type: 2-pin magnetic dock

Connectivity & Features

• Bluetooth 5.3 (supports calls via smartphone link)
• NFC (Mastercard® & Visa® payments, region-dependent)
• Speaker & Dual Microphones
• Wireless OS: Xiaomi HyperOS 2
• Compatibility: Android 8.0+, iOS 14.0+

Durability

• 5ATM Water Resistance (50m depth, swim-proof)

• Not for diving, sauna, or high-pressure water jets

Health & Fitness

• 24/7 Heart Rate, SpO2, Stress, Sleep Monitoring

• 60-Second Health Report (quick wellness check)

• Breathing Exercises (relaxation, focus, sleep aid)

• 150+ Sports Modes (running, skiing, cycling, etc.)

• Running Coach & Form Analysis (vertical ratio, stride metrics)

• Fall Detection (Skiing Mode) – Auto-emergency call if no response

Smart Features

• Xiaomi Smart Hub (control Xiaomi Home devices*)

• Remote Camera Control

• Find My Phone

• Gesture Controls (quick actions via hand movements)

• Third-Party App Sync (Strava, Suunto, Health Connect)