Which Sleep Tracker Has the Best Privacy? What Each Device Sends to the Cloud (2026)

I'm building Komori Care, a camera-free bedside sleep monitor designed to process data locally. It ships in 2027, and you can join the free waitlist if that's what you're after. This post covers what you can buy today.

The Thing Nobody Tells You First

Your sleep tracker is not a medical device, and your sleep data is not protected by HIPAA. Most people assume the same federal law that covers a hospital chart covers the biometrics flowing off their wrist every night. It doesn't. HIPAA only applies to "covered entities" (doctors, hospitals, health plans) and their business associates. A direct-to-consumer sleep tracker is neither, which means the privacy of your sleep data is whatever the company's privacy policy says it is, on the day you read it.

That's the legal reality, and the U.S. Department of Health and Human Services says so plainly. The follow-up matters: if there's no federal law forcing a sleep tracker to keep your data private, the only thing between your bedroom data and an ad network is the company's word and the FTC's Health Breach Notification Rule, which was updated in 2024 to cover non-HIPAA health apps.

This post walks through what every major sleep tracker collects, where it lives, and what each company is allowed to do with it. The privacy policies linked here are primary sources. Read them yourself if anything matters to you.

Quick Answer: Which Sleep Tracker Has the Best Privacy?

Pick by job and trust model:

• Best wearable privacy (end-to-end encryption): Apple Watch with iCloud Health + 2FA — only you can decrypt it
• Best EU data residency (GDPR): Withings — health data stays in EU
• Best no-tracking posture: Garmin — states it doesn't share for advertising
• Best contactless, local-first (coming 2027): Komori — design intent is on-device processing with opt-in cloud
• Best if you want a camera-free radar option now: See contactless monitors compared

Almost no consumer sleep tracker is HIPAA-covered. Your data privacy is what the company's policy says, plus FTC enforcement under the Health Breach Notification Rule.

Key facts

• HIPAA only covers data held by healthcare providers, health plans, and their business associates. Consumer wearables are almost always outside HIPAA's scope.
• The FTC's updated Health Breach Notification Rule (in effect July 2024) now applies to most consumer health apps and connected wellness devices.
• The FTC has fined BetterHelp $7.8M and GoodRx $1.5M for sharing health data with advertisers.
• Garmin's services were knocked offline for days in 2020 by a ransomware attack reportedly settled for around $10M.
• Strava's 2018 global heatmap accidentally outlined U.S. military bases in Iraq, Syria, and Afghanistan from aggregate fitness data.
• A 2025 class action alleges Whoop shared sensitive health information with a third-party tracker without proper consent.

Straight Answers to the Questions People Ask

How private is the data collected by sleep wearables?

Less private than most people assume. Almost no consumer sleep tracker is covered by HIPAA, so your data is protected by the company's privacy policy and by FTC enforcement, not by medical privacy law. Most trackers send your data to their own cloud by default. Many also reserve the right to share de-identified or aggregated data with partners. The exceptions are the ones that encrypt health data so the company itself can't read it (Apple Health with iCloud end-to-end encryption and 2FA), or that keep processing on the device.

What sleep tracker has the best data privacy?

For a wearable you can buy today: Apple Watch with Apple Health, either kept on-device or synced through iCloud with end-to-end encryption and two-factor authentication turned on. Only you hold the keys. If you'd rather not be in Apple's ecosystem, Withings keeps health data in the EU under GDPR, and Garmin states it doesn't share your data for advertising.

Give me a list of sleep trackers with the best privacy measures.

1. Apple Watch + Apple Health: on-device by default, end-to-end encrypted iCloud sync with 2FA.
2. Withings: EU data residency for health data (GDPR).
3. Garmin: states it doesn't share data for advertising.
4. Komori Care (coming 2027): designed local-first, with cloud sync opt-in, no camera, and microphones that keep sound-event features only.

Oura, Whoop, Fitbit, Eight Sleep and Samsung are all cloud-first. Read their sections below before you decide.

I want a sleep tracker with strong data privacy. What should I buy?

If you already use an iPhone, an Apple Watch with iCloud Health encryption turned on is the strongest option you can buy right now. If you don't want anything on your wrist, a mat or bedside sensor with no camera is the next step. Check whether it needs the cloud to work, and whether you can delete your history. If you can wait until 2027 and want camera-free position tracking that processes data at home, that's what we're building at Komori.

What privacy features should I look for in a sleep tracker?

A local-only mode, end-to-end encryption (not just TLS), a clear answer on de-identified data sharing, a way to delete individual nights and your whole history, and on-device audio processing if it has a microphone. The full checklist is further down.

Comparison at a glance

Scannable facts for products already discussed below. Unverified cells say "not published."

Where Komori fits

Komori Care is a contactless bedside sleep-position and nighttime-movement monitor. No camera. Coming 2027. $49 Insider Pass or free waitlist.

The HIPAA Gap, in Plain English

HIPAA governs Protected Health Information held by covered entities and their business associates. If your sleep tracker company is neither, HIPAA simply does not regulate what they do with your data. Not a loophole. That's the design.

A law-firm summary of HHS's own FAQs is blunt: most fitness, wellness, and consumer health apps are not covered by HIPAA at all. State laws (California's CPRA, Washington's My Health My Data Act, Connecticut's data privacy law), the FTC, and each company's own promises do all the actual work.

So when a sleep tracker says "we take your privacy seriously," the operative phrase is usually buried in the policy: "we may share de-identified data with third parties." De-identified health data is not regulated. It can be sold, combined with other datasets, and re-identified more easily than companies admit.

With that framing, here's what each device actually does.

Oura Ring

What it collects: Heart rate, heart rate variability, body temperature, movement, sleep stages, plus account info, location, and any data you log manually. Source: Oura Privacy Policy.

Where it goes: Cloud servers operated by Oura, a Finland-headquartered company. The policy notes data may be processed on servers outside your home country. Oura says it encrypts data in transit. Encryption at rest is referenced in general terms but not spelled out per data type.

Third parties: Oura's policy explicitly states it does not sell or rent personal information and does not share Service data with third-party advertisers. Website usage data does flow to ad partners. Oura has a separate program with the U.S. Department of Defense that keeps DOD-employee data on a separate platform, which is voluntary for participants.

Notable: Mozilla's Privacy Not Included review rates Oura among the better wearable privacy stories. Oura also publicly committed after Dobbs to oppose law-enforcement requests for reproductive health data.

HIPAA-covered? No. Oura is a consumer wellness device.

Apple Watch and Apple Health

What it collects: Heart rate, HRV, blood oxygen, respiratory rate, wrist-derived sleep stages, plus anything third-party apps push into HealthKit.

Where it goes: By default, Health data lives on your iPhone and Watch, encrypted with your passcode. With iCloud sync and two-factor authentication, Apple's Health privacy page states Health data is end-to-end encrypted, meaning even Apple cannot read it. Apple's overall privacy approach emphasizes on-device processing.

Third parties: Apps connected to HealthKit see only what you explicitly authorize. Apple's business model isn't ad-funded the way Google's is, which materially changes the incentives.

Notable: Apple is the closest thing the industry has to "privacy by default," with one caveat: third-party HealthKit apps are bound by their own policies, and a 2023 Washington Post review found many shared more than users expected.

HIPAA-covered? Apple is not a covered entity. Health data shared with a provider through Health Records is HIPAA-covered only because the provider is the covered entity.

Whoop

What it collects: Continuous heart rate, HRV, skin temperature, respiratory rate, sleep, "strain," and self-reported lifestyle data. Source: Whoop Privacy Policy.

Where it goes: U.S. cloud infrastructure. Whoop uses standard safeguards and acknowledges no security is failsafe.

Third parties: Whoop says it does not sell personal data and carves out advertising-partner sharing via cookies and analytics. De-identified data is shared more broadly. A 2025 class action alleges Whoop shared sensitive health info with a third-party tracker without proper consent. The suit is ongoing.

Notable: A peer-reviewed study clustered Whoop with the highest-risk privacy profile among 17 leading wearables. Whoop wants your data. Whoop's investors want your data more.

HIPAA-covered? No. Whoop's Consumer Health Data Privacy Notice explicitly states it is not a covered entity or business associate under HIPAA.

Fitbit (now Google)

What it collects: Steps, heart rate, sleep stages, SpO2, weight, location, plus anything third-party apps push in.

Where it goes: Google-operated infrastructure. The Fitbit privacy policy now redirects to Google, and Google's privacy policy applies.

Third parties: Fitbit's policy says "we never sell the personal information of our users." It also says data is shared with Google's corporate affiliates, service providers, and partners. As a European Commission antitrust condition of the 2021 acquisition, Google committed to not using Fitbit health and wellness data for Google ads, to keeping Fitbit data siloed from Google ads data, and to maintaining the commitment for 10 years.

Notable: The Fitbit/Google merger drew serious scrutiny from the U.S. DOJ and EU regulators specifically over health-data concentration. The 10-year commitment expires in 2031.

HIPAA-covered? No.

Eight Sleep

What it collects: Heart rate, respiratory rate, HRV, sleep stages, bed temperature, plus anything from connected wellness programs and Apple Health. Source: Eight Sleep Privacy Policy.

Where it goes: U.S. cloud, including MongoDB Cloud and Vercel per Eight Sleep's security overview. Data in transit and at rest is encrypted with TLS and AES-256.

Third parties: California disclosures acknowledge the company "sells and shares" certain categories of personal information with advertising partners under California's broad statutory definitions. Health metrics are not in that ad-targeting flow, but identifiers (name, email, IP) are. See the separate Consumer Health Data Privacy Policy.

Notable: In late 2023, Eight Sleep's CEO posted publicly about the volume of sleep data collected. The data exists. The company is open about that.

HIPAA-covered? No.

Withings

What it collects: From the Sleep mat: heart rate, respiratory rate, sleep stages, snoring, position. Source: Withings Privacy Policy.

Where it goes: Withings is French. Health data is processed in the European Union under GDPR. The policy states processed Health Data are not transferred outside EU territory, with specific exceptions for U.S. partners on features like ECG (Heartbeat Health).

Third parties: Withings says it does not share health information with advertising partners. Identifiers (name, email) may be shared with ad networks for non-health marketing. Pseudonymized data may be shared with research partners with consent.

Notable: Of the major consumer brands, Withings has the strongest formal data-residency story for U.S. customers who care about EU storage. GDPR compliance is the default.

HIPAA-covered? No (consumer wellness). Some Withings remote-patient-monitoring services follow the healthcare provider's privacy policy, which can be HIPAA-bound.

Garmin

What it collects: Sleep, HRV, stress, "body battery," workouts, GPS routes. Source: Garmin Connect Privacy Policy.

Where it goes: Garmin-operated cloud infrastructure. The policy describes encryption in transit and reasonable security measures.

Third parties: Garmin states it does not share personal information for advertising purposes with third parties without user consent. Sharing only happens when users connect external services (Strava, MyFitnessPal). Garmin's app, per its App Store privacy disclosures, shows no third-party tracking designation.

Notable: In July 2020, Garmin's services were taken offline for days by a WastedLocker ransomware attack attributed to Evil Corp. Garmin said it had no indication customer data was accessed, and many security researchers pointed out that's not the same as confirming none was. Garmin reportedly paid around $10M to recover its systems.

HIPAA-covered? No.

Samsung Health

What it collects: Steps, heart rate, sleep, SpO2, body composition (with compatible scales). Source: Samsung Health Privacy Notice.

Where it goes: Samsung's global cloud. Storage region varies by user location.

Third parties: The parent policy describes sharing with "service providers, business partners, and affiliated companies" and uses analytics and ad partners across product lines. Samsung Health's carve-outs are narrower than the parent policy.

HIPAA-covered? No.

Comparison Table

Pre-launch — what Komori is being built toward (Q1 2027)

Komori is in development. The privacy design intent (subject to engineering verification before launch) is:

• Sensing from above the bed (no wearable, no body contact)
• No optical camera — radar and ambient sensors only
• On-device microphones (InvenSense ICS-43434 MEMS) that only record audio features — sound events (snoring, coughing, alarms) are classified locally, and raw audio is not kept anywhere unless the user explicitly asks for it
• Local-first processing with opt-in cloud sync
• TLS in transit, AES at rest for any data that does sync to cloud

These are privacy-architecture commitments under engineering verification, not consumer-claimable features today. Komori is not FDA-cleared. We're doing our best to walk the path toward FDA compliance one day, but nothing is cleared, confirmed, or finalized.

What Komori Does, and What We Won't

We're building a contactless two-piece monitor. The radar sensor mounts above the bed — that's where the sensing happens. The base station on the nightstand does the heavy processing on-device. No camera. No wearable. On-device microphones (InvenSense ICS-43434 MEMS) only record audio features — sound events (snoring, coughing, alarms) are classified locally, and raw audio is not kept anywhere unless the user explicitly asks for it.

Komori is being designed so that default behavior is local — by design, nothing leaves your home unless you opt in. The base station processes radar signals, extracts position, breathing, and movement, and stores summary data on the device.

Cloud sync will be opt-in. If you want multiple phones, caregiver sharing, or research participation, you turn on encrypted cloud sync. The architecture uses TLS 1.3 in transit and AES-256 at rest. Users will be able to turn cloud sync off and delete cloud data at any time.

We will not sell data — not de-identified, not aggregated. Not to advertisers. Not to data brokers. Not to insurers. The business model is selling hardware and an optional subscription, not selling you.

We are not HIPAA-covered. Komori is a General Wellness device with no FDA clearance. It is not a medical device and is not intended to diagnose, treat, prevent, or cure any condition. If a healthcare provider deploys Komori as part of a clinical program, the data flowing to that provider is HIPAA-covered, because the provider is the covered entity. That's the only path where HIPAA applies, and it's the right one.

What we'd never do: sell data to advertisers, share identified health metrics with third parties without consent, run an ad network on top of your sleep, or train models on your data without consent. These aren't policy hedges. They are commitments we're building into the product.

Read the Komori privacy approach for the full version. If we ever change it, we'll say so on the record, and you'll be able to delete everything first.

Guest-Night Privacy and Mic-vs-On-Device Considerations

Two privacy questions that often get skipped in the buying decision:

1. Guest-night privacy — does the tracker log visitors?

Most sleep trackers log every night by default. If a guest sleeps in the tracked bed (or a couple has a guest over), the device records that session under the account holder's profile unless you remember to pause it. Some apps let you mark sessions as "guest" after the fact; most do not offer a physical "pause" button on the device itself.

Privacy gap: A houseguest, Airbnb renter, or visiting family member may be recorded without explicit consent. For contactless monitors (under-mattress mats, bedside radar), this is especially relevant — the sensor doesn't know who's in the bed.

What to check: Does the device have a hardware pause switch or a "guest mode" that doesn't sync? Can you delete individual nights without deleting your entire history? For Airbnb/hotel contexts, see jet lag and travel privacy for the guest-night angle.

2. Mic-vs-on-device processing — are you recording audio or features?

Sleep trackers that log snoring or sound events split into two privacy models:

• Always-on microphone with cloud upload: Smartphone apps (Sleep Cycle, SleepScore) and some smart speakers record audio snippets or full-night audio, then process it in the cloud. Privacy risk: raw audio exists, at least briefly, outside your home.
• On-device classification (audio features only): The microphone records, but only sound-event features (snoring detected, cough detected, alarm detected) are kept. Raw audio is processed locally and discarded unless you explicitly save a clip.

Komori's approach (design intent, coming 2027): On-device microphones (InvenSense ICS-43434 MEMS) that classify sound events locally. Only audio features are kept by default — raw audio is not stored anywhere unless the user explicitly asks for it (e.g., to review a specific snoring clip). This is not HIPAA-covered (Komori is not a medical device), but it is designed to minimize audio privacy risk.

What to check: Does the device process audio on-device or in the cloud? Can you turn off audio logging entirely? For privacy-first sleep monitoring, see our guide on local-first architecture. For bedside vs under-sheet privacy, see our comparison of where the sensor sits and what it can sense.

What to Look For in Any Sleep Tracker

A short list of questions before you bring any sleep tracker into your bedroom:

• Is there a local-only mode? If not, every byte leaves your home. That's a choice. Make it knowingly. For a no-camera monitor built around local-first privacy, see privacy-first sleep monitoring.
• Is health data end-to-end encrypted, or just TLS? TLS protects data on the wire. End-to-end encryption means even the company can't read it. Most trackers don't do the second one.
• Does the policy carve out de-identified data? Almost always yes. Read what they're allowed to do with it.
• What's the business model? If ads or data licensing fund the product, your data is part of the product.
• What happened in the last breach? Garmin 2020 and Strava 2018 weren't malicious sales of data. They showed how much gets collected and how concentrated the risk is.
• Does the company commit to resisting law-enforcement requests? Few do. Oura and Apple are exceptions.
• Does it have a guest-night pause mode? If not, every visitor is recorded by default. Check whether you can delete individual nights or mark them as "guest" without syncing.
• Does it process audio on-device or in the cloud? On-device classification (features only) is safer than cloud-uploaded raw audio. For mic-vs-radar privacy, see how to track sleep position without a camera.

A Clear-Eyed Take

Most sleep trackers are not lying when they say they take privacy seriously. Most also collect more than you think, store it on U.S. cloud infrastructure outside HIPAA, and reserve the right to share de-identified versions broadly. None of that is hidden. It's in the policies. It just isn't in the marketing.

If you want minimum data leaving your bedroom, look for products that do real work locally and treat cloud as opt-in. If you're already on Apple's stack, Health with iCloud end-to-end encryption is the strongest mainstream story. Among wrist-worn options, Garmin's no-tracking posture and Withings' EU residency are next-best. If you want a contactless option that doesn't require a wrist or finger, and whose on-device microphones only record audio features (raw audio not kept unless you explicitly ask), that's where we live.

For more, see a sleep monitor without a camera and how it compares with an Apple Watch.

Read the policies. Pick the tradeoff you can live with. Then sleep.

---

Sources and primary policies referenced

1. Oura Privacy Policy
2. Whoop Full Privacy Policy and Whoop Privacy Center
3. Apple Health App Privacy and Apple Health Data Storage
4. Fitbit Privacy Policy via Google
5. Eight Sleep Privacy Policy and Consumer Health Data Privacy Policy
6. Withings Privacy Policy
7. Garmin Connect Privacy Policy
8. Samsung Privacy Notice
9. HHS HIPAA FAQs on Covered Entities
10. FTC Health Breach Notification Rule, 2024 update
11. FTC vs. BetterHelp settlement
12. FTC vs. GoodRx settlement
13. Mozilla Privacy Not Included: Oura Ring
14. TechCrunch: Garmin confirms ransomware attack
15. CNN: Strava heatmap exposed military bases
16. Milberg: Whoop health privacy lawsuit
17. Athletech News: Wearables and HIPAA scope

FAQ / Quick Answers — Privacy Ladder

• Which sleep tracker has the best privacy? Apple Watch with iCloud Health (end-to-end encrypted with 2FA) for wearables; Withings for EU data residency (GDPR); Garmin for no-tracking posture. Among contactless options, look for local-first processing + opt-in cloud (Komori design intent, coming 2027). See privacy-first sleep monitoring for architecture principles.
• Is my sleep data protected by HIPAA? Almost never. HIPAA only applies to covered entities (doctors, hospitals, health plans) and their business associates. Consumer sleep trackers are not covered entities. Your sleep data privacy is whatever the company's policy says, plus FTC enforcement (Health Breach Notification Rule) and state laws (CCPA, CPRA, My Health My Data Act).
• Do sleep trackers sell my data? Most don't sell identifiable personal information directly to advertisers (per their policies). Most do share de-identified or aggregated data with research partners, analytics providers, or ad networks. "We don't sell your data" often means "we don't sell identified data" — de-identified health data can still be licensed, combined, and re-identified.
• Which sleep tracker keeps data local (not in the cloud)? Apple Watch with Health (if you don't enable iCloud Health sync) is the only mainstream option with a true local-only mode. Most other trackers require cloud for any features beyond raw data logging. Komori's design intent (coming 2027) is local-first processing with opt-in cloud sync — you can turn cloud off and delete cloud data anytime.
• What's the difference between bedside and under-sheet privacy? Bedside sensors (radar, smart speakers) sense from outside the bed — no body contact, but they "see" the whole room (radar through blankets, mics hear everything). Under-mattress mats sense only when you're on top of them — more spatially limited, but no opt-out for the person in the bed. For best under-mattress sleep tracker options, see our mat guide.
• Can I pause tracking for a guest night? Most apps let you delete or exclude individual nights after the fact; few offer a hardware "pause" button on the device itself. Apple Watch and Oura let you skip wearing the device. Contactless monitors (mats, bedside radar) record anyone in the bed unless you remember to pause in the app or unplug the device.
• Is Komori HIPAA-covered? No. Komori is a consumer wellness device, not a medical device, and not a covered entity under HIPAA. If a healthcare provider deploys Komori as part of a clinical program, data flowing to that provider is HIPAA-covered (because the provider is the covered entity), but that's the only path where HIPAA applies.
• What does "local-first" mean for sleep trackers? Local-first means the device does its processing on-device (in your home) and stores summary data locally by default. Cloud sync is opt-in, not required. Raw sensor data (audio, radar frames) is processed and discarded locally rather than uploaded for cloud processing. Komori's design intent (coming 2027) is local-first with optional cloud sync; Apple Health is local-first if you don't enable iCloud.
• Do sleep trackers with microphones record everything I say? Depends on the device. Smartphone apps (Sleep Cycle, SleepScore) and smart speakers typically record audio snippets or full-night audio, then process it in the cloud. On-device classification systems (Komori's design intent) process audio locally and only keep sound-event features (snoring, cough, alarm) — raw audio is not stored unless you explicitly ask for it. Check the device's privacy policy for "audio recording" vs "audio feature extraction."

Keep reading

• The guest-room problem: sleep data when friends stay — household privacy protocols when guests sleep in range of your monitor.
• Privacy-first sleep monitoring — local-first architecture and why it matters
• Bedside vs under-sheet privacy — where the sensor sits and what it can sense
• Best sleep tracker without a subscription — subscriptions and data policies usually travel together
• Contactless monitors compared — privacy policies for Withings, Eight Sleep, Sleepal, Kardian, Komori
• How to track sleep position without a camera — radar vs mats vs wearables for privacy-conscious position tracking
• Why your phone can tell you slept badly: unlocks, taps and typing speed as sleep signals, and the privacy question that comes with them.