Garmin Forerunner 170 Music vs Garmin Forerunner 255

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Forerunner 170 Music compared with Forerunner 255

	GarminForerunner 170 Music	GarminForerunner 255
Overview
Released
Released	May 2026	June 2022
Display
Case sizes
Case sizes	42.6 mm	46 mm
Panel
Panel	OLED	Memory-in-pixel
Always-on display
Always-on display	Yes	Yes
Display detail
Display detail	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	1.3-inch (33 mm) transflective colour memory-in-pixel display, 260 x 260 pixels; button-operated.
Screen protection
Screen protection	Chemically strengthened glass	Corning Gorilla Glass 3.
Health and fitness
ECG
ECG	No	No
Blood oxygen
Blood oxygen	Yes	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	Dual-band (L1 and L5)
Water resistance
Water resistance	50 m	50 m
Sensors
Sensors	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	GPS, GLONASS, Galileo, multi-frequency GNSS, Garmin Elevate wrist heart rate, Pulse Ox, barometric altimeter, compass, gyroscope and accelerometer.
Health features
Health features	Continuous heart rate with high/low alerts; HRV status; Body Battery; stress and respiration; advanced sleep, sleep coach, breathing variations and nap detection; meditation; smart wake alarm; Health Snapshot; lifestyle logging; Health Status; women's health tracking via Garmin Connect; no ECG app	Pulse Ox, HRV status, sleep score, all-day stress and Body Battery energy monitoring.
Fitness features
Fitness features	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	Triathlon and open-water swimming profiles, morning report, race widget, daily suggested workouts, training status and load, recovery time and PacePro; breadcrumb course guidance.
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	Incident detection and assistance require a paired smartphone; LiveTrack.
Battery and connections
Battery life (maker's claim)
Battery life (maker's claim)	Up to 10 days	Up to 14 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	iPhone and Android	iPhone and Android
Storage
Storage	4 GB	–
Battery life detail
Battery life detail	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; with music, GPS-only up to 7.5 hours and all-systems up to 6.5 hours (exact series manual; UK web table mislabels 7.5 hours as days); actual life depends on enabled features and usage	Up to 14 days in smartwatch mode, 30 hours in GPS-only mode or 16 hours with all-systems multi-band GNSS.
Charging
Charging	Garmin proprietary plug charging/data cable; rechargeable built-in lithium-ion battery; USB charging temperature 0–45 °C	Rechargeable battery with Garmin charging cable.
Connectivity
Connectivity	Bluetooth, ANT+ and Wi-Fi; 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 and plays downloaded personal audio or supported music-service content through compatible Bluetooth headphones; third-party services may require subscriptions; no speaker/microphone calls or cellular connection	Bluetooth and ANT+; Garmin Pay, Connect IQ, smart notifications and phone music controls. This standard model does not store music.
Storage
Storage	4 GB memory/history with offline music support	–
Design
Weight (lightest version)
Weight (lightest version)	41 g (better)	49 g
Software
Software	Garmin	Garmin
Case materials
Case materials	Fibre-reinforced polymer bezel; silicone band; chemically strengthened glass; 5 ATM water rating; operating/storage temperature –20–60 °C	Fibre-reinforced polymer bezel and silicone band; 5 ATM water rating.
Size
Size	42.6 x 42.6 x 11.9 mm; Garmin lists 41 g without a separate body-only weight	45.6 x 45.6 x 12.9 mm; 49 g.
Bands
Bands	Standard 20 mm quick-release two-tone silicone band; fits 126–203 mm wrists	Quick-release 22 mm band; fits wrists 130–205 mm.
Colours
Colours	Black with Black/Amp Yellow band; Whitestone with Whitestone/Cloud Blue band; Teal Green with Teal Green/Citron band; Red Pink with Red Pink/Mango band	Tidal blue with black bezel.
In the box
In the box	Forerunner 170 Music; charging cable; documentation	–