Garmin fēnix 3 HR vs Garmin fēnix 8 Solar

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fēnix 3 HR compared with fēnix 8 Solar

	Garminfēnix 3 HR	Garminfēnix 8 Solar
Overview
Released
Released	2016	August 2024
Display
Case sizes
Case sizes	51.5 mm	47 mm or 51 mm
Panel
Panel	Memory-in-pixel	Memory-in-pixel
Always-on display
Always-on display	Yes	Yes
Display detail
Display detail	1.2-inch (30.4 mm) transflective colour MIP display, 218 x 218 pixels, with button controls.	Always-visible sunlight-readable transflective colour memory-in-pixel (MIP) touchscreen, five leakproof inductive buttons. 47 mm: 33 mm (1.3 inch), 260 x 260 pixels. 51 mm: 35.56 mm (1.4 inch), 280 x 280 pixels.
Screen protection
Screen protection	Domed sapphire lens.	Power Sapphire solar charging lens
Health and fitness
ECG
ECG	No	Yes
Blood oxygen
Blood oxygen	No	Yes
Skin temperature
Skin temperature	No	Yes
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	100 m	100 m
Sensors
Sensors	GPS, GLONASS, Garmin Elevate optical wrist heart rate, barometric altimeter, three-axis compass and accelerometer.	GPS, GLONASS, Galileo, QZSS and BeiDou; SatIQ automatic multi-band selection; Garmin Elevate wrist heart rate, Pulse Ox, barometric altimeter, compass, gyroscope, accelerometer, thermometer, ambient light and depth sensor to 40 m.
Health features
Health features	All-day heart rate, steps and sleep tracking; intensity minutes.	Garmin ECG App where regionally available with compatible phone and watch software; Pulse Ox availability varies by country. HRV status, Body Battery, health status/snapshot, skin temperature, sleep coach/score/alignment, breathing variations, nap detection, stress/respiration tracking, lifestyle logging, jet lag adviser and menstrual-cycle/pregnancy tracking. Current maker table includes smart wake alarm and past ovulation estimates.
Fitness features
Fitness features	Running, cycling, swimming, triathlon, hiking, skiing, golf and rowing profiles; breadcrumb courses and TracBack; VO2 max estimate, recovery advisor and race predictor. Stride length, ground-contact balance and vertical ratio require a compatible chest strap.	Training readiness/status, training load/focus/effect, endurance and hill scores, running tolerance, running power/dynamics, PacePro, ClimbPro, real-time stamina and recovery time. Running economy and step speed loss require a compatible accessory. Garmin running, cycling, strength and triathlon coaching. Scuba single-gas air/nitrox (21–40% oxygen) and apnea modes, EN 13319 depth sensor to 40 m; dive rating is distinct from 10 ATM surface water resistance. Golf, ski, climbing, cycling, swimming, multisport and strength activity profiles. Preloaded TopoActive maps on these Sapphire versions, downloadable regional maps over Wi-Fi, dynamic round-trip routing, NextFork, routes and turn-by-turn directions; golf and SkiView maps. Optional Outdoor Maps+ subscription adds premium maps. No need for a phone to follow stored maps/routes.
Safety features
Safety features	–	LED flashlight with white/red light and strobe. Incident detection, assistance, LiveTrack and live event sharing require a compatible paired phone and appropriate connectivity. Can control a separate compatible inReach device; LTE/satellite/SOS built into fēnix 8 Pro are not features of this Solar model.
Battery and connections
Battery life (maker's claim)
Battery life (maker's claim)	Up to 14 days	Up to 30 days
In low-power mode
In low-power mode	–	Up to 48 days
Mobile data option
Mobile data option	No	No
Works with
Works with	iPhone and Android	iPhone and Android
Storage
Storage	–	32 GB
Battery life detail
Battery life detail	Up to two weeks in smartwatch mode with 24/7 heart rate, 16 hours in GPS training mode or 40 hours in UltraTrac mode. Garmin's launch release also stated up to three weeks in watch mode without the same smartwatch use.	Headline figures are 51 mm without solar: up to 30 days smartwatch and 48 days battery-saver watch mode. 47 mm: smartwatch 21 days/28 with solar; saver 34/58 days; GPS-only 67/92 h; all satellites 48/59 h on current UK web table (September 2026 owner guide instead says 49 h with solar); multi-band 37/43 h; all satellites plus music 13 h; maximum-battery GPS 132/283 h; expedition 34/58 days. 51 mm: smartwatch 30/48 days; saver 48/107 days; GPS-only 95/149 h; all satellites 68/92 h; multi-band 52/65 h; music 18 h; maximum-battery GPS 186/653 h; expedition 50/118 days. Solar watch/saver/expedition claims assume all-day wear with three hours daily outside at 50,000 lux; GPS solar claims assume use outside at 50,000 lux, with typical SatIQ use for multi-band. Actual battery life depends on enabled features.
Charging
Charging	Rechargeable 300 mAh lithium-ion battery with USB charging cable.	Garmin proprietary plug cable to USB-C computer port or AC adaptor rated at least 5 W, per current owner guide. Lithium-ion battery. Solar charging stops when fully charged or connected to external power.
Connectivity
Connectivity	Bluetooth, ANT+ and Wi-Fi; smart notifications, Connect IQ, Garmin Connect and LiveTrack through a paired phone.	Bluetooth, ANT+ and Wi-Fi. Calls use a paired phone; offline watch voice commands and voice notes use the built-in microphone/speaker. Garmin Messenger requires a paired phone/app for ordinary messages. Garmin Pay with supported banks; downloaded local music or supported subscription music services; Connect IQ apps and Garmin Share.
Storage
Storage	32 MB built-in memory, with 23 MB available; up to 1,000 waypoints and 30 routes.	–
Design
Weight (lightest version)
Weight (lightest version)	86.1 g	80 g (better)
Software
Software	Garmin	Garmin
Case materials
Case materials	PVD stainless steel bezel and buttons, reinforced housing and treated silicone band; 10 ATM water rating.	Titanium bezel (natural or Carbon Grey DLC), fibre-reinforced polymer case and metal rear cover; silicone band.
Size
Size	51.5 x 51.5 x 16 mm; 86.1 g with silicone band.	47 mm: 47 x 47 x 15.2 mm. 51 mm: 51 x 51 x 15.4 mm. Silicone wrist fit: 125–208 mm (47 mm), 127–210 mm (51 mm). QuickFit 22 mm and 26 mm bands respectively. 47 mm 80 g with band, 57 g case only; 51 mm 95 g with band, 67 g case only. Headline weight describes 47 mm with supplied silicone band.
Reference and release detail
Reference and release detail	–	Maker announced 27 August 2024; its Italian launch page states both Solar sizes were available that day. UK first shipping day is not independently established.
Colours
Colours	Dark grey case with black silicone band.	–