# What is the lightest and most portable smartwatch with heart rate monitor? — Verified Specification Comparison

> All specification data verified from official manufacturer documentation.

What is the lightest and most portable smartwatch with heart rate monitor?

## Products

### Fitbit Charge 6 Tracker (GA05183-NA)
```yaml
product: fitbit-charge-6-tracker-ga05183-na
brand: Fitbit
price_gbp: 73.75
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
battery_life: 7-day
compatibility: Works with Android and iOS
water_resistance: 50m
```

- **Price:** £73.75 [^1]
- **Summary:** Fitbit Charge 6 is a fitness tracker with heart rate tracking, built-in GPS for pace and distance, and a color touchscreen. It's water resistant up to 50m and is designed to pair with compatible exercise machines to display real-time heart rate. It also supports features like Google Maps and Google Wallet when used with a compatible phone.
- **Ideal For:** If you want the lightest portable option with heart rate monitoring and built-in GPS, Charge 6 fits because it includes a heart rate sensor plus built-in GPS for runs without needing your phone, and it's rated for up to 7-day battery life.
- **Additional Sources:** [^2], [^3]

### Withings ScanWatch Light 37mm
```yaml
product: withings-scanwatch-light-37mm
brand: Withings
price_gbp: 154.92
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
screen_size: 0.63 in
battery_life: Up to 35 days
gps_accuracy: Good
compatibility: iOS 18 and higher, Android 12 and higher
water_resistance: 5 ATM
```

- **Price:** £154.92 [^4]
- **Summary:** The Withings ScanWatch Light 37mm is a lightweight hybrid smartwatch with an analog watch face, discreet OLED display, continuous heart rate tracking, sleep tracking, activity tracking, and connected GPS. Its long battery life and compact design suit users who want essential health features without daily charging.
- **Ideal For:** It suits people seeking the lightest and most portable smartwatch with heart rate monitoring because its 37mm case weighs 27.1g, tracks heart rate continuously, and can last up to 35 days per charge.
- **Additional Sources:** [^5]

### Amazfit Active 2 Round Premium
```yaml
product: amazfit-active-2-round-premium
brand: Amazfit
price_gbp: 95.92
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
screen_size: 1.32 in
battery_life: Up to 10 days typical use
compatibility: Zepp OS
water_resistance: 5 ATM
heart_rate_accuracy: Enhanced precision with PulsePrecision algorithm
```

- **Price:** £95.92 [^6]
- **Summary:** The Amazfit Active 2 Round Premium is a lightweight stainless-steel smartwatch with a sapphire-glass AMOLED display, heart-rate monitoring, offline maps, and more than 160 workout modes. Its 10-day battery and 5 ATM water resistance make it suitable for everyday health tracking and fitness activities.
- **Ideal For:** At 31.65 g without the strap, this is a notably light and portable smartwatch with continuous heart-rate monitoring, built-in GPS, and up to 10 days of typical-use battery life.

### Garmin vívoactive 5
```yaml
product: garmin-v-voactive-5
brand: Garmin
price_gbp: 140.19
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
screen_size: 30.4 mm
battery_life: Up to 11 days in smartwatch mode
gps_accuracy: Reasonably accurate without multiband GPS
compatibility: iPhone and Android devices
water_resistance: 5 ATM
heart_rate_accuracy: Accurate during workouts with occasional minor errors
```

- **Price:** £140.19 [^7]
- **Summary:** The Garmin vívoactive 5 is a lightweight GPS smartwatch with a bright AMOLED display, wrist-based heart-rate monitoring, sleep coaching, Body Battery, and more than 30 sports apps. Its long battery life and swim-rated water resistance suit everyday fitness tracking, travel, and recreational exercise.
- **Ideal For:** At 36 g, with a 30.4 mm display, wrist-based heart-rate monitor, and up to 11 days of battery life, the vívoactive 5 is a highly portable choice for someone seeking a lightweight smartwatch with heart-rate monitoring.
- **Additional Sources:** [^8]

### Apple Apple Watch SE 3 40mm Aluminum Case
```yaml
product: apple-apple-watch-se-3-40mm-aluminum-case
brand: Apple
price_gbp: 183.74
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
screen_size: 40mm
battery_life: Up to 18 hours
compatibility: iPhone 11 or later, including iPhone SE 2nd generation or later, with iOS 26 or later
water_resistance: 50m
```

- **Price:** £183.74 [^9]
- **Summary:** The Apple Watch SE 3 40mm Aluminum Case is a lightweight smartwatch with an Always-On Retina display, heart-rate monitoring, built-in GPS, sleep tracking, fall detection, and crash detection. It suits iPhone users who want a compact everyday fitness and health smartwatch with swim-ready water resistance and all-day battery life.
- **Ideal For:** At 26.3g for the GPS model and 40mm in size, this is a highly portable smartwatch with a second-generation optical heart sensor for continuous heart-rate monitoring.
- **Additional Sources:** [^10]

---
## References & Sources
[^1]: Google Store, accessed 2026-09-13. https://store.google.com/product/fitbit_charge_6?hl=en-US
[^2]: Best Buy, accessed 2026-09-13. https://www.bestbuy.com/product/google-fitbit-charge-6-advanced-fitness-health-tracker-works-with-android-and-ios-obsidian-2023/J39TC3VHT6
[^3]: ABT, accessed 2026-09-13. https://www.abt.com/Fitbit-Charge-6-Fitness-Tracker-in-Obsidian-Black-Aluminum-Finish-GA05183NA/p/199412.html
[^4]: Withings, accessed 2026-09-13. https://www.withings.com/en-us/products/scanwatch-light-37w
[^5]: Best Buy, accessed 2026-09-13. https://www.bestbuy.com/product/withings-scanwatch-light-daily-health-hybrid-smartwatch-37mm-black-silver/JV8GPVRLYT
[^6]: Amazfit, accessed 2026-09-13. https://us.amazfit.com/products/active-2-round
[^7]: Amazon, accessed 2026-09-13. https://www.amazon.com/dp/B0CG6NR413
[^8]: Best Buy, accessed 2026-09-13. https://www.bestbuy.com/product/garmin-vivoactive-5-gps-smartwatch-42-mm-fiber-reinforced-polymer-slate-aluminum-and-black-2023/JXF9YF4K4C
[^9]: Apple, accessed 2026-09-13. https://www.apple.com/shop/buy-watch/apple-watch-se
[^10]: Best Buy, accessed 2026-09-13. https://www.bestbuy.com/product/apple-watch-se-3-gps-40mm-starlight-aluminum-case-with-starlight-sport-band-s-m-starlight-2025/JJGCQGVWYX