fitbit
Pick Fitbit if
- You want one device on your wrist 24/7
- ECG, AFib, VO2max from the watch itself
- Google ecosystem (Pixel, Maps, Android)
Fitbit vs Withings
Fitbit covers everyday wrist signals — HR, HRV, sleep, SpO2, VO2max, ECG. Withings owns body composition and clinical signals — muscle mass, blood pressure, sleep apnea screening, AFib.
fitbit
22/33signals its devices cover
Daily-wear watch + scale
vs
withings
29/33signals its devices cover
Scale, BP monitor, watch
QUICK VERDICT
These two are complementary, not competitors. Fitbit gives you the wrist signal stack. Withings adds the things a watch physically cannot measure: muscle and water distribution, blood pressure, sleep apnea, body temperature. Both brands sell a scale, but only Withings still sells one that reads body fat: Fitbit's current Aria Air weighs you and stops there, and the Aria 2 that did read it is discontinued.
COVERAGE BY CATEGORY
Where each brand actually wins
Per-category breakdown of health signals exposed by each vendor's developer API. The number is breadth, not quality.
SIGNAL BY SIGNAL
The full matrix
| Signal | Fitbit | Withings |
|---|---|---|
| Heart & Vitals | ||
| Resting HR | ✓ | ✓ |
| HRV | ✓ | ✓ |
| SpO2 | ✓ | ✓ |
| Respiratory Rate | ✓ | ✓ |
| Skin Temperature | ✓ | ✓ |
| Body Temperature | — | ✓ via BeamO |
| Blood Pressure | — | ✓ via BPM Core |
| ECG recording | ✓ | ✓ |
| AFib detection | ✓ | ✓ |
| Vascular age | — | ✓ via Body Scan 2 |
| Sleep | ||
| Sleep duration | ✓ | ✓ |
| Sleep stages | ✓ | ✓ |
| Sleep score | ✓ | ✓ |
| Sleep efficiency | ✓ | ✓ |
| Sleep apnea index | — | ✓ |
| Activity | ||
| Steps | ✓ | ✓ |
| Active minutes | ✓ | ✓ |
| Calories | ✓ | ✓ |
| Activities | ✓ | ✓ |
| Floors climbed | ✓ | ✓ |
| Distance | ✓ | ✓ |
| Fitness & Recovery | ||
| VO2max | ✓ | ✓ |
| Training load | ✓ | — |
| Recovery / Readiness | ✓ | — |
| Body Battery | — | — |
| Stress (continuous) | ✓ | — |
| Cardiovascular age | — | ✓ via Body Scan 2 |
| Body Composition | ||
| Weight | ✓ via Fitbit Aria Air | ✓ via Body Scan 2 |
| Body fat % | — | ✓ via Body Scan 2 |
| Muscle mass | — | ✓ via Body Scan 2 |
| Hydration | — | ✓ via Body Scan 2 |
| Bone mass | — | ✓ via Body Scan 2 |
| Visceral fat | — | ✓ via Body Scan 2 |
Verified against vendor developer documentation and MyBodyAI backend code. This counts what a brand's API exposes, which is not the same question as what one device measures: the device catalog scores each model's own hardware, so its numbers differ.
Current Fitbit models Google Fitbit Air (2026), Google Pixel Watch 4 (2025), Google Pixel Watch 3 (2024), Fitbit Charge 6 (2023), all 8 Fitbit devices
Current Withings models Body Scan 2 (2026), BodyFit (2026), BPM Vision (2025), BeamO (2025), all 14 Withings devices
WHICH ONE FOR YOU
Pick the one that matches your priority
withings
Pick Withings if
- You're tracking weight, body fat, muscle mass
- Blood pressure or sleep apnea screening matter
- You prefer a scale over a wristband
fitbit+withings
Pick both if
- Fitbit Charge or watch for HRV + sleep + ECG
- Withings scale + BP monitor for body composition + clinical
- Merged feed reaches 32/33 unique signals across both devices
FAQ
Frequently asked questions
Can I use Fitbit and Withings together?
Yes, and they complement each other. Withings measures what a watch cannot on its own, body composition from a smart scale, blood pressure, and on some models an ECG. Many people keep Fitbit for daily tracking and add a Withings device for the rest.
Which one tracks more health signals?
Fitbit tracks 22 of the 33 signals I compare, Withings tracks 29. The matrix above breaks it down by category, and they often win different categories.
Which one should I get first?
Start with whichever covers your main goal. For daily heart rate, sleep and workouts, go with Fitbit. For weight, body composition and blood pressure, go with Withings. You can add the other later.
How did you compare Fitbit and Withings?
From each brand's official spec sheets and support pages, cross-checked against independent hands-on reviews (DC Rainmaker, the5krunner, Tom's Guide). Signal-level edge cases are noted in the matrix, not hidden behind a single check mark.
WHERE TO BUY
Check prices at the source
Links to each vendor's store. None of them changed any pick above.
MORE COMPARISONS
Explore other pairs
OPTIONAL — IF YOU WANT MORE
Want one place that merges both feeds?
MyBodyAI is what I build with these signals — it pulls from any combination of the brands above and derives Biological Age and 12 health indices from the raw numbers. Free to try, no card. It's optional — the comparison above stands on its own.
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