Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Google - Fitbit Charge 6 | Xiaomi - Smart Band 9 |
|---|---|---|
| Battery life | 7 days | 21 days |
| Sport modes | 40 | 150 |
| GPS | true | false |
Between the Fitbit Charge 6 and Smart Band 9, the Fitbit Charge 6 comes out ahead in gps, while the Smart Band 9 wins on battery life / sport modes. Overall, the Fitbit Charge 6 scores 77.4 and the Smart Band 9 scores 75.8 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (77.4 vs 75.8). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the Fitbit Charge 6 if you care most about gps. The biggest gaps in its favor are gps. The single most decisive one: Has GPS.
Pick the Smart Band 9 if you care most about battery life / sport modes. Its strongest claims are battery life, sport modes. The single most decisive one: Battery life — 200.00% more. 21 days vs 7 days.
Both ship with comparable spo2, water resistance, 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: Google - Fitbit Charge 6 or Xiaomi - Smart Band 9?
Google - Fitbit Charge 6 leads the current Mars Score by 1.6 points.The more useful decision is the trade-off behind that result: compare battery life, gps against the way you will actually use the product.
Choose Google - Fitbit Charge 6 if…
Google - Fitbit Charge 6 has the measurable edge on has gps.
Choose Xiaomi - Smart Band 9 if…
Xiaomi - Smart Band 9 has the measurable edge on battery days, sport modes.
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 Google - Fitbit Charge 6 wins
- ▲Has GPS.
Why Xiaomi - Smart Band 9 wins
- ▲Battery life — 200.00% more. 21 days vs 7 days.
- ▲Sport modes — 110.00 more. 150 vs 40.
Spec comparison
Fitness
| Spec | Google - Fitbit Charge 6 | Xiaomi - Smart Band 9 |
|---|---|---|
| Form factor | Band | Band |
| GPS | truelead | false |
| Heart rate | true | true |
| SpO2 | true | true |
| Sleep tracking | true | true |
| Sport modes | 40 | 150lead |
Battery
| Spec | Google - Fitbit Charge 6 | Xiaomi - Smart Band 9 |
|---|---|---|
| Battery lifeⓘ | 7 days | 21 dayslead |
| Water resistanceⓘ | 5 ATM | 5 ATM |
Design
| Spec | Google - Fitbit Charge 6 | Xiaomi - Smart Band 9 |
|---|---|---|
| Display size | 1.04 " | 1.62 "lead |
| Weight | 37 g | 16 glead |