Garmin Forerunner 15 vs Garmin Forerunner 170

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Forerunner 15 compared with Forerunner 170

	GarminForerunner 15	GarminForerunner 170
Overview
Released
Released	2014	May 2026
Display
Case sizes
Case sizes	52 mm or 57 mm	42.6 mm
Panel
Panel	Memory-in-pixel	OLED
Always-on display
Always-on display	Yes	Yes
Display detail
Display detail	Monochrome memory-in-pixel display, 55 × 32 pixels; 2.1 × 2.0 cm on the small version and 2.5 × 2.4 cm on the large version, with a backlight and four-button control.	1.2-inch (30.4 mm diameter) colour AMOLED touchscreen, 390 x 390 pixels; optional always-on display and large-font setting; five physical buttons
Screen protection
Screen protection	–	Chemically strengthened glass
Health and fitness
ECG
ECG	No	No
Blood oxygen
Blood oxygen	No	Yes
Skin temperature
Skin temperature	No	No
Sleep apnoea alerts
Sleep apnoea alerts	No	No
High blood pressure alerts
High blood pressure alerts	No	No
Body composition
Body composition	No	No
Fall detection
Fall detection	No	No
Crash detection
Crash detection	No	No
GPS
GPS	Single-band	Single-band
Water resistance
Water resistance	50 m	50 m
Sensors
Sensors	Built-in GPS; supports a chest-worn heart-rate monitor and optional ANT+ foot pod for indoor pace and distance.	Garmin Elevate wrist heart rate; Pulse Ox; barometric altimeter; compass; gyroscope; accelerometer; thermometer; ambient light sensor; thermometer measures activity/ambient temperature, not overnight skin temperature
Health features
Health features	Daily steps, calories and inactivity reminders; heart-rate recording requires the chest strap sold in some bundles.	Continuous heart rate with high/low alerts; HRV status; Body Battery; stress and respiration; advanced sleep, sleep coach, breathing variations and nap detection; smart wake alarm; Health Snapshot; lifestyle logging; Health Status; women's health tracking via Garmin Connect; no ECG app
Fitness features
Fitness features	Outdoor pace, distance, personal records, Auto Lap, Auto Pause, Virtual Pacer and run/walk intervals; indoor distance requires the foot pod.	More than 80 sports apps; training readiness, status, load, load focus and recovery time; Garmin running, cycling and strength coaching; daily suggested running workouts and quick workouts; wrist-based running dynamics and running power; ground-contact balance requires a compatible accessory; PacePro and grade-adjusted pace; VO2 max and race predictions; cycling power-meter and Varia radar/light support; pool and open-water swimming; no dedicated triathlon mode; Breadcrumb course navigation, point-to-point navigation, back-to-start and TracBack; elevation profile, future elevation plot and Up Ahead; no full routable offline maps
Safety features
Safety features	–	Incident detection during selected activities, assistance and LiveTrack require a paired compatible smartphone; live event sharing is Android-only; screen flashlight, not a separate LED torch
Battery and connections
Battery life (maker's claim)
Battery life (maker's claim)	Up to 35 days	Up to 10 days
In low-power mode
In low-power mode	–	Up to 19 days
Mobile data option
Mobile data option	No	No
Works with
Works with	No phone pairing	iPhone and Android
Storage
Storage	–	4 GB
Battery life detail
Battery life detail	Up to five weeks in watch/activity-tracking mode or eight hours with GPS on.	Smartwatch up to 10 days, or 4 days with display always on; battery saver smartwatch up to 19 days; GPS-only GNSS up to 20 hours; all-systems GNSS up to 14 hours; actual life depends on enabled features and usage
Charging
Charging	Rechargeable lithium-ion battery with a USB charging and data cable.	Garmin proprietary plug charging/data cable; rechargeable built-in lithium-ion battery; USB charging temperature 0–45 °C
Connectivity
Connectivity	USB connection to a Mac or PC for Garmin Connect uploads; no Bluetooth or direct smartphone sync. ANT+ supports optional heart-rate and foot-pod accessories.	Bluetooth and ANT+; GPS, GLONASS and Galileo; no multi-band GNSS; Garmin Pay contactless payments; Android-only text responses and notification images; Connect IQ apps/watch faces/data fields; Garmin Share; controls smartphone music without offline playback; no Wi-Fi, speaker/microphone calls or cellular connection
Storage
Storage	Seven activities of on-watch history.	4 GB memory/history; standard Forerunner 170 does not support offline music playback
Design
Weight (lightest version)
Weight (lightest version)	36 g (better)	41 g
Software
Software	Garmin	Garmin
Case materials
Case materials	Plastic case and band; 5 ATM water rating.	Fibre-reinforced polymer bezel; silicone band; chemically strengthened glass; 5 ATM water rating; operating/storage temperature –20–60 °C
Size
Size	Small 4.0 × 5.2 × 1.6 cm and 36 g; large 4.6 × 5.7 × 1.6 cm and 43 g. The longest case dimensions appear in the size comparison.	42.6 x 42.6 x 11.9 mm; Garmin lists 41 g without a separate body-only weight
Bands
Bands	–	Standard 20 mm quick-release two-tone silicone band; fits 126–203 mm wrists
Colours
Colours	Small black/green, teal/white and violet/white; large black/blue and red/black.	Black with Black/Amp Yellow band; Whitestone with Whitestone/Cloud Blue band; Teal Green and Red Pink belong to the separate Music model
In the box
In the box	Watch, charging/data cable and manual; a chest heart-rate monitor was included in some bundles.	Forerunner 170; charging cable; documentation