How to choose a smartwatch when you want control over your data

Smartwatch reviews almost all play the same show: battery, GPS endurance, sensors, bezel, activity rings. Very few discuss who actually owns your data, how easy it is to take it out, how an API changes when the manufacturer gets acquired. This guide tries to fill that gap: it gives you criteria to choose a wearable starting from data control instead of marketing features.

We won't tell you 'buy X'. We'll say: here are the use archetypes, here are the real trade-offs between brands, here are common red flags. Final call is yours.

What 'data control' actually means

'Data control' is an overused phrase. When we use it here we mean five precise things, in order of practical importance:

1. Native exportability: I can download all my data in common formats (CSV, JSON, GPX, FIT) without emailing support or reverse-engineering undocumented APIs.
2. Pipeline transparency: I know where my data goes. On-device? Manufacturer cloud? Sold to ad-tech? Can I read the privacy policy and figure it out in 5 minutes?
3. Permission granularity: can I tell the ecosystem 'yes HR, no GPS' or is it all-or-nothing?
4. Interoperability: can I use my device with third-party apps (Strava, Komoot, alternative health apps) without asking the manufacturer's permission?
5. Switch resilience: if the brand gets acquired or shuts down a division tomorrow, do I have a Plan B?

The four use archetypes

Before looking at models, identify which profile you recognize yourself in. They're simplifications — reality is fuzzy, but they help cut noise.

Serious athlete (endurance, performance)

You run marathons, race triathlons, do ultra-trails, or follow a structured plan. The data you need: precise GPS, estimated VO₂ max, training load, recovery time, intra-workout HRV, detailed HR zones. You need a device that survives 8+ hours with active GPS and a serious analytics platform.

• •Default: Garmin (Forerunner 265/965, Fenix 8, Enduro). Native FIT/GPX export, official API, Connect IQ community.
• •Alternative: Polar Vantage V3 or Grit X2 Pro. Strong sleep coaching and Recovery Pro, full export via Polar Flow.
• •Outsider: Coros Apex 2 Pro. Fewer features, but full export and aggressive pricing.
• •Avoid: Apple Watch for ultra (limited GPS battery), Fitbit Sense (light performance metrics).

Longevity nerd (HRV, sleep, biomarkers)

You care more about HRV stability over time, sleep quality by stage, SpO₂, skin temperature, respiratory rate, occasional ECG. You've read Attia, follow Huberman, do zone 2. You need sensor precision for the night, not for runs.

• •Default: Oura Ring Gen 4. Top-tier sleep sensors, official API, monthly subscription (caveat: full data behind paywall).
• •Alternative: Whoop 4.0. Subscription-only, no display, pure HRV/recovery focus. Export available but limited.
• •For those who want a watch too: Garmin Venu 3 or Forerunner 265 — Garmin Sleep Score + nightly HRV without subscription lock.
• •Smart scales: add Withings Body Comp or Body Cardio. Health Mate has full export and stable API.

Daily user (notifications, light fitness, basic health)

You walk, do light gym, track steps and sleep, want wrist notifications. You don't need Body Battery or Training Readiness — you need something that lasts 5 days without charging and doesn't waste your time. Data control is 'just in case', not a daily priority.

• •Default Android: Galaxy Watch 7 or Watch Ultra. Native Health Connect, solid Samsung Health ecosystem, great value.
• •Default iOS: Apple Watch SE (3rd gen) — no equivalent alternative as iPhone integration.
• •Budget Android: Xiaomi Mi Band 9 or Xiaomi Watch Active. Mi Fitness writes to Health Connect, low cost, excellent battery life.
• •Pixel native: Pixel Watch 3 if you're already in Google ecosystem. Caveat: uses Fitbit as backend, so doubly dependent on Google.

Parent monitoring / care

You want to monitor an aging parent, a family member with a chronic condition, or your child. Critical data: fall detection, anomalous HR, location (optional), irregular heart rhythm. Priority is sensor reliability + ease of selective data sharing with you (or a doctor), not performance analytics.

• •Default: Apple Watch SE or Series 10 with Family Setup. ECG, fall detection, Emergency SOS are reliable. Closed ecosystem but here it's a feature, not a bug.
• •Android alternative: Galaxy Watch 7 with ECG. Samsung Health has caregiver sharing in some countries.
• •For sharing medical data: Withings ScanWatch 2 — continuous ECG + SpO₂, report integration via Health Mate, well accepted by European doctors.
• •Kids: dedicated devices (Garmin Bounce, Fitbit Ace) — privacy-bounded by design, no social, no open chat.

Cross-cutting red flags

Regardless of model, there are patterns that should make you pause before swiping the card.

• •Companion app unavailable in Europe or not updated for 12 months. Indicator of low sales → discontinuation risk → your data orphaned.
• •Official API documented but requires 'enterprise contact'. Translation: closed for personal use, only accessible to commercial partners. Historical example: Huawei Health Kit outside China has significant barriers.
• •Export only possible via email to support. Means it's not a feature but a concession: it can be revoked or face arbitrary delays.
• •Brand-new brand with unclear investors. Nice to support indies, but for health data choose entities with at least 5 years of history and public financials.
• •Privacy policy saying 'we share aggregated data with research partners'. Even aggregated and anonymized data can be de-anonymized with cross datasets. Read the details.

Price vs functionality: the real mental model

Stop comparing €200 vs €600 in absolute terms. Think in cost per year of effective use. A Garmin Forerunner lasting 5 years at €350 = €70/year. A Whoop at €30/month subscription for 5 years = €1800. An Apple Watch at €450 you'll probably replace in 3 years = €150/year + iPhone dependency.

Ecosystem lock-in: the hidden cost

When you buy a smartwatch, you don't just buy the device — you also marry a companion app, a cloud, and typically a phone. How much does it cost to switch ecosystems two years from now?

• •Apple Watch → Android: ~100% history loss (Apple Health is iOS-only, no readable Android export). Hard lock-in.
• •Galaxy Watch → other Android: Samsung Health history exportable as CSV, importable into Health Connect. Soft lock-in, manageable.
• •Garmin Watch → other brand: full FIT/GPX export, but proprietary metrics (Body Battery, Training Status) have no direct equivalents. Medium lock-in.
• •Fitbit → other: Google Takeout works, data in JSON. Low lock-in (for now — depends on Google's decisions).
• •Oura → other: official API provides full data to those who know how to download it. Low technical lock-in, but high psychological (Oura metrics are distinctive).

What I'd do today (May 2026)

Opinionated section, declared as such. Not a buying recommendation or personalized advice.

• •If I were a serious Android runner: Garmin Forerunner 265 + Withings Body Comp for weight.
• •If I were a sleep nerd: Oura Ring Gen 4 + a Galaxy Watch 7 for activity/notifications. Pricey combo but covers everything.
• •If I were a budget Android daily user: Xiaomi Mi Band 9 — €50, syncs via Health Connect, does 90% of what's needed.
• •If I were an iOS daily user: Apple Watch SE 3rd gen. Accept lock-in as the price of convenience.
• •If I were monitoring a parent: Apple Watch or Withings ScanWatch 2, depending on the wearer's phone.

A checklist to not screw up

Before buying, install the companion app on the phone you already have. Check it exists in your language and country. Google '[model] privacy policy data export'. Read the latest 5 one-star reviews on Play Store / App Store: that's where you find the real day-to-day issues. If everything holds up, go ahead.

1. ✓ Companion app available in my country and updated in the last 6 months
2. ✓ Export documented (search 'data export' in official FAQ)
3. ✓ Health Connect sync (Android) or HealthKit (iOS) confirmed
4. ✓ Privacy policy readable in 10 minutes, no 'we share with unspecified partners' clauses
5. ✓ Brand with at least 5 years of history or solid European warranty
6. ✓ Cost per year of expected use aligned with my budget
7. ✓ At least one alternative third-party app exists that can read my data if I change my mind