Garmin Forerunner 935Garmin Forerunner 945
Tech specs 
Size47 x 47 x 13.9mm47 x 47 x 13.7 mm
MaterialLens material: glass
Bezel and case material: fiber-reinforced polymer
Lens material: Corning® Gorilla® Glass DX
Bezel and case material: fiber-reinforced polymer
ChargingYesYes
BatteryLithium-ionLithium-ion
Battery lifeUp to 24 hours in GPS mode with optical HR; up to 2 weeks in watch mode including optical HR, activity tracking and smart notifications; up to 60 hours in UltraTrac modeSmartwatch Mode: Up to 2 weeks; GPS mode with music: Up to 10 hours; GPS mode without music: Up to 36 hours
Water-resistance5 ATM5 ATM
Weight49 g50 g
SensorGPS/GLONASS, barometric altimeter, compass, accelerometer, gyroscope, thermometer, heart rateGPS/GLONASS/GALILEO, barometric altimeter, compass, accelerometer, gyroscope, thermometer, heart rate, Pulse OX
Display240 pixel diameter; sunlight-visible, transflective memory-in-pixel (MIP)240 pixel diameter; sunlight-visible, transflective memory-in-pixel (MIP)
Screen size30.4mm diameter1.2" (30.4 mm) diameter
ColorsSlate Gray, Silver, Champagne - comes with interchangeable bands in various colors.Black, Blue
OtherPLATFORM: Home Grown OS
PROCESSOR: Unknown
MEMORY: 64 MB
CONNECTIVITY: WiFi, Bluetooth
PLATFORM: Home Grown OS
PROCESSOR: Unknown
MEMORY: 200 hours of activity data
CONNECTIVITY: Bluetooth, ANT+, Wi-Fi
Activity tracking 
StepsYesYes
DistanceYesYes
Calories burnedYesYes
ActivityYesYes
FloorsYesYes
SleepYesYes
Heart rate24/724/7
Stress & recoveryYesYes
Pulse OxYes
Respiration rate
UV exposure
Skin temperature
Galvanic skin response
Hydration level
Calorie intake
GPSGPS and GLONASS enabledGPS/GLONASS/GALILEO
Running featuresVO2 max estimate, recovery advisor, race predictor, running dynamics, calculates distance for indoor workouts, personal records, virtual partner/racerGPS-based distance, time and pace, Running dynamics (with compatible accessory), cadence, performance condition, run workouts, race predictor, foot pod compatible.
Swimming featuresLengths, distance, pace, stroke count/rate, calories; stroke type identification; open water swim metrics; swim workoutsPool swim metrics (lengths, distance, pace, stroke count/rate, calories), Stroke type detection (freestyle, backstroke, breaststroke, butterfly), Swim efficiency (SWOLF), drill logging, pool swim workouts.
Other - Physiological measurements: Yes (Recovery time, lactate threshold, FTP, HRV Stress Test, V02 Max for running and cycling, Race Predictor, Training Status, Training Load, Anaerobic Training Effect)
- Running Dynamics (with optional accessory)
- Performance condition
- Run/walk feature: Yes
- many other features...
Custom alerts: Yes
Customisable lap screen
Connect IQ™ support: Yes (watch faces, data fields, widgets and apps)
Wireless connectivity: yes
UltraTrac: Yes
- outdoor recreation, golf and cycling features
- Physiological measurements: Vo2Max, Training Status, Training Load, Recovery Time, Training Effect, Heat and altitude acclimation, Training load focus, Primary benefit (Training Effect labels) and more.
- Body Batter Energy Monitor
- Incident detection
Non-fitness functions 
Smartphone notificationsYesYes, Text response/reject phone call with text (Android™ only)
On-board music storageUp to 1000 songs, Plays and controls watch music
Connected payYes
LTE
Links 
Affiliate link*AmazonAmazon | Garmin
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