The Fitbit Versa 4 is a fitness-focused smartwatch designed to help you track your activity, monitor your health and stay connected. Buy the Fitbit Versa 4 online at Gadgets Nerd.

Design and Build:

• Dimensions: 1.59 inches (40.5 mm) length, 1.59 inches (40.5 mm) width, 0.44 inches (11.2 mm) height  
• Weight: 0.08 lb (37.64 g)  
• Materials: Aluminum watch case and buckle, flexible silicone band.  
• Display: 1.58-inch AMOLED color touchscreen with Corning Gorilla Glass 3. Offers vibrant visuals and good visibility.  
• Water Resistance: Up to 50 meters (164 feet), suitable for swimming and showering.  
• Colors: Available in Black/Graphite Aluminum, Waterfall Blue/Platinum Aluminum and Copper Rose Aluminum.  
• Comfort: Thin and lightweight design for comfortable all-day wear and during workouts.  
• Physical Button: Features a physical side button for easier navigation, a change from the capacitive button on the Versa 3.  

Battery and Power:

• Battery Life: 6+ days on a single charge (varies with usage).  
• Charging Time: 0-100% in approximately 2 hours.
• Battery Type: Lithium-polymer.  
• Fast Charging: Provides a full day's charge in just 12 minutes.

Sensors and Components:

• Multi-path optical heart rate sensor (PurePulse 2.0 for continuous heart rate tracking).  
• Red and infrared sensors for SpO2 monitoring (blood oxygen saturation).  
• Built-in GPS + GLONASS for tracking pace and distance during outdoor activities without your phone.  
• 3-axis accelerometer for tracking steps, activity, and sleep.  
• Altimeter for tracking elevation changes.  
• Ambient light sensor for automatic screen brightness adjustment.  
• NFC for Fitbit Pay/Google Wallet (contactless payments).  
• Vibration motor for notifications and alarms.  
• Speaker (75dB SPL @ 10cm) for calls and voice assistant interactions.  
• Microphone for calls and voice assistant.  
• Device temperature sensor (skin temperature variation available in the Fitbit app).  
• Wi-Fi: Deactivated, cannot be turned on.  

Fitness and Activity Tracking:

• 40+ Exercise Modes: Track various workouts like running, cycling, swimming, strength training, HIIT, yoga, and more, with real-time stats on your wrist.  
• Automatic Exercise Recognition (SmartTrack): Automatically detects and records certain activities.  
• Active Zone Minutes: Tracks time spent in different heart rate zones (Fat Burn, Cardio, Peak) to help optimize workouts.  
• Daily Readiness Score (with Fitbit Premium): Assesses if your body is ready for exercise or needs recovery based on activity, sleep, and heart rate variability.  
• 24/7 Heart Rate Tracking: Continuous monitoring of heart rate, resting heart rate, and heart rate zones.  
• Steps, Distance, and Calories Burned Tracking: Monitors your daily activity levels.  
• Cardio Fitness Score (VO2 Max estimate): Provides an estimate of your overall fitness level.  
• Workout Intensity Map (in the Fitbit app): Shows your heart rate zones throughout your GPS-tracked routes.
• Reminders to Move: Encourages you to take 250 steps each hour.  

Sleep Tracking and Analysis:

• Automatic sleep tracking, including light, deep, and REM sleep stages.  
• Sleep Score to help you understand the quality of your sleep.  
• Sleep Profile (with Fitbit Premium): Provides a monthly breakdown of 10 key sleep metrics.  
• Smart Wake Alarm: Wakes you during an optimal stage of sleep.  
• Do Not Disturb and Sleep Mode.  

Health Monitoring:

• Heart Rate Variability (HRV) tracking (in the Health Metrics dashboard).  
• Breathing Rate tracking (in the Health Metrics dashboard).  
• High and Low Heart Rate Notifications.
• Irregular Heart Rhythm Notifications (AFib detection).
• SpO2 Monitoring (blood oxygen saturation) during sleep (in the Health Metrics dashboard).  
• Skin Temperature Variation tracking (in the Fitbit app).  
• Menstrual Health Tracking: Log periods, track symptoms, and estimate ovulation windows (in the app).  
• Wellness Report (with Fitbit Premium): Generates a PDF of your health metrics.  
• Stress Management Score (with Fitbit Premium): Assesses your body's response to stress based on heart rate, activity, and sleep.  
• Guided Breathing Sessions.
• Reflection Logging (in the Fitbit app).  

Smart Features:

• On-wrist Bluetooth Calls: Answer calls, send callers to voicemail, and adjust volume when your phone is nearby. (Android only)  
• Call, Text & App Notifications: Receive alerts from your smartphone (compatible with Android 11.0+ and iOS 16.4+). Android users can send quick and voice replies.  
• Amazon Alexa Built-in: Get news and weather, set alarms, control smart home devices, and more using voice commands.  
• Google Maps: Get turn-by-turn directions on your wrist (phone must be nearby, available on Android, coming to iOS).  
• Google Wallet (Fitbit Pay): Make contactless payments.  
• Find My Phone.
• Customizable Clock Faces: Choose from numerous designs.
• Apps: Access a selection of Fitbit apps for various functions.
• Music Control: Control music playback on your phone (Spotify, Deezer, Pandora).

Connectivity and Compatibility:

• Bluetooth 5.0.
• Syncing Range: Up to 30 feet (9 meters).
• Smartphone Compatibility: Requires the Fitbit app, compatible with most popular phones running:   
  • Android OS 11.0 or higher.  
  • Apple iOS 16.4 or higher.  
• Requires a Google account for setup and use.

Fitbit Premium:

The Fitbit Versa 4 includes a 6-month trial of Fitbit Premium, which unlocks additional features like:

• Daily Readiness Score.
• Personalized insights.
• Advanced sleep analysis with Sleep Profile.
• Stress Management Score with detailed breakdown.
• Hundreds of guided workouts and mindfulness sessions.
• In-depth health metrics trends and analysis.

Verdict, the Fitbit Versa 4 is a well-rounded smartwatch that offers a comprehensive suite of fitness tracking, health monitoring, and smart features, making it a strong contender for users looking to improve their well-being and stay connected.