Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Garmin - Fenix 8 (47mm) | Garmin - Venu 4 |
|---|---|---|
| Battery life | 384 h | 264 h |
| Weight | 73 g | 45 g |
| Water resistance | 10 ATM | 5 ATM |
Between the Fenix 8 (47mm) and Venu 4, the Fenix 8 (47mm) comes out ahead in battery life / water resistance, while the Venu 4 wins on weight. Overall, the Fenix 8 (47mm) scores 71.9 and the Venu 4 scores 73.6 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (71.9 vs 73.6). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the Fenix 8 (47mm) if your top frustration with your current device is running out of charge before the day ends — endurance is the lead spec here. The biggest gaps in its favor are battery life, water resistance. The single most decisive one: Battery life — 45.45% more. 384 h vs 264 h.
Pick the Venu 4 if you carry the device everywhere and weight or thickness has been the deciding factor before. Its strongest claims are weight. The single most decisive one: Weight — 28.00 g less. 45 vs 73.
Both ship with comparable ecg, display size, cellular, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: Garmin - Fenix 8 (47mm) or Garmin - Venu 4?
Garmin - Venu 4 leads the current Mars Score by 1.7 points.The more useful decision is the trade-off behind that result: compare battery life against the way you will actually use the product.
Choose Garmin - Fenix 8 (47mm) if…
Garmin - Fenix 8 (47mm) has the measurable edge on battery life h, water resistance atm.
Choose Garmin - Venu 4 if…
Garmin - Venu 4 has the measurable edge on weight g.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Garmin - Fenix 8 (47mm) wins
- ▲Battery life — 45.45% more. 384 h vs 264 h.
- ▲Water resistance — 5.00 ATM more. 10 vs 5.
Why Garmin - Venu 4 wins
- ▲Weight — 28.00 g less. 45 vs 73.
Spec comparison
Design
| Spec | Garmin - Fenix 8 (47mm) | Garmin - Venu 4 |
|---|---|---|
| Case size | 47 mmlead | 45 mm |
| Weight | 73 g | 45 glead |
| Case material | fiber-reinforced polymer | aluminum |
| Water resistanceⓘ | 10 ATMlead | 5 ATM |
Display
| Spec | Garmin - Fenix 8 (47mm) | Garmin - Venu 4 |
|---|---|---|
| Display size | 1.4 " | 1.4 " |
| Always-on display | true | true |
| Peak brightnessⓘ | 1000 nits | 1000 nits |
Health & Fitness
| Spec | Garmin - Fenix 8 (47mm) | Garmin - Venu 4 |
|---|---|---|
| ECG | true | true |
| SpO2 | true | true |
| Temperature sensor | true | true |
| Sleep tracking | true | true |
| Blood pressure | false | false |
Battery & Connectivity
| Spec | Garmin - Fenix 8 (47mm) | Garmin - Venu 4 |
|---|---|---|
| Battery lifeⓘ | 384 hlead | 264 h |
| GPS | true | true |
| Cellular | false | false |
| NFC | true | true |
| OS | Garmin OS | Garmin OS |
Frequently asked
Which has longer battery life, Fenix 8 (47mm) or Venu 4?+
Fenix 8 (47mm) lasts 384 hours vs 264 hours.
Do Fenix 8 (47mm) or Venu 4 support ECG?+
Both support ECG.
Which has cellular, Fenix 8 (47mm) or Venu 4?+
Neither offers cellular.