Who Can See Your Smartwatch Health Data? Settings to Check

Where your health data actually lives

Your smartwatch measures health signals like heart rate, blood oxygen, sleep stages, and activity using sensors. Those numbers are first stored in the watch's internal memory, then passed to your paired phone over a short-range wireless link, and finally synced to a cloud account associated with the platform you use. Each step has different privacy implications.

On Apple platforms, health information is collected in the Health app on iPhone and in watchOS, and you control what apps can read and write that data. On Wear OS by Google, health and fitness data flows through Google Fit or the watch maker's app, and it is tied to your Google Account. In both cases, the watch itself holds recent data, but the full history usually lives in the cloud.

The key point: your health data is not a single file in one place. It is copied across devices and servers, so you need to check permissions at every layer: the watch, the phone, and the cloud account dashboard.

How sharing and cloud sync work

Cloud sync is what makes your data available across devices, but it also means a company's server holds copies of your health records. Apple's Health app syncs via iCloud, Google's Wear OS syncs via Google servers, and Samsung, Garmin, and other makers run their own platforms. Each provider's privacy policy is the contract that states how your data is used for service improvement or analytics.

When you install a third-party app on your watch or phone, you are often granting it access to health data. For example, a workout app you download from an app store might ask for permission to read your heart rate or sleep data. If you grant it, that app's developer can see the data, subject to its own privacy rules. The FDA's guidance distinguishes between general wellness products and medical devices, and this matters: a wellness app is not held to the same standards as a medical device, so you should be more careful about what you share with wellness apps.

You can revoke these permissions at any time from the settings app on your phone. On iPhone, go to Settings > Privacy > Health. On Android, check Google Fit or the wearables app under Settings > Apps > Permissions.

Account settings that control who sees your data

The single most important setting is your watch passcode or lock screen. Without it, anyone who picks up your watch can see your heart rate, notifications, and health summaries. Enable the passcode in the watch settings, and set it to require the passcode when you take the watch off. This is the first line of defense.

Beyond the lock, review these settings on the paired phone:

Go through these settings on your watch and phone:

• Enable a passcode lock on the watch and set it to require the passcode when worn off-wrist.
• Open the health app on your phone and review which third-party apps can read and write data.
• Turn off activity sharing or remove specific people from your shared list.
• Review the wearables companion app's privacy settings and disable cloud sync if you prefer local-only storage.
• On family devices, check the parent's phone to see what health data is visible from the child's watch.

What the company can see and what you can do about it

Even with all sharing turned off, the watch maker and its cloud service still hold a copy of your health data. That is a consequence of using a cloud-connected device. You can limit the sensitivity of what is uploaded: for example, some platforms let you disable blood oxygen or ECG uploads while keeping activity ring data in the cloud. Check your platform-specific settings.

You also have the right to request a copy of your data or ask the company to delete it. Both Apple and Google provide export tools that download your health records as standard files. Deleting your account removes the cloud copy, but check the effect on the watch: after deletion, the watch may reset and lose local history.

For children's watches, the rules are stricter. The FTC's Children's Online Privacy Protection Act requires services directed at kids under 13 to obtain parental consent before collecting personal information. That means a kids' smartwatch maker must give you, the parent, clear notice about what data it collects and how to control it. When you set up a child's watch, you should receive a privacy notice and have the right to review, change, or delete the data collected about your child.

Weighing convenience against privacy

Cloud sync is what makes features like sleep trends over months, GPS route history, and cross-device health dashboards possible. If you turn off all sync, you lose those conveniences and the watch becomes a simple fitness tracker. Most users accept some level of cloud storage because the value outweighs the privacy cost, but you can choose a more privacy-focused setup: keep sync on but restrict third-party app access, or use a watch that supports local-only mode.

If privacy is your top priority, look for watches that let you disable cloud features entirely and store data only on the phone. Some Wear OS watches let you use them without signing into a Google account, though you lose app store access. Apple Watch requires an iPhone and an Apple Account for setup, but you can still turn off health data sharing to non-Apple apps. For detailed guidance on choosing between platforms, see our comparison of Apple vs Android smartwatch ecosystems and the platform lock-in explainer.

A practical privacy checklist for your smartwatch

Take ten minutes to run through these steps. They cover the most likely places where your data is visible.

Run through the following checklist:

• Turn on the watch passcode and set the wrist-detection feature so the watch locks when you take it off.
• Review the health app permissions on your phone and remove any app that does not need health data.
• Check the Wear OS or watchOS app store settings to see which apps have sensor access.
• Open the watch maker's companion app and read its data sharing controls. Turn off any 'share with third parties' option.
• If you use activity sharing, remove people you no longer want to see your rings.
• For kids' watches, read the COPPA privacy notice that should appear at setup, and exercise your right to review the data collected about your child.
• Set a calendar reminder to recheck these settings every six months, because app updates and new app installs can grant new permissions.

Choosing a watch with the privacy controls you need

The level of control you get depends heavily on the platform. Apple's watchOS and the iPhone's Health app give you granular per-app controls over health data categories like heart rate, sleep, and ECG. Google's Wear OS uses the Android permission model, which also allows per-app access, but the exact wording of permissions depends on the app developer. You should check the privacy settings of any app before installing it on your watch.

If your main concern is preventing the watch maker from seeing your data, consider device families that emphasize on-device processing. However, even those watches need to sync to a phone app, so you cannot avoid the phone entirely. The best choice is a watch whose platform you understand and whose privacy controls you can manage. Our buying guides compare watches across platforms, including the best watchOS smartwatches, the best Wear OS smartwatches, and the best Garmin smartwatches if you prefer a more dedicated fitness platform.

You should also consider how the watch maker handles data when you sell or trade the watch. Before resale, you should unpair the watch and reset it to factory defaults, which erases local data and disconnects the cloud account. Our guide on preparing your smartwatch for resale walks through the steps.

What to pick for your use

Questions

Can my employer see my smartwatch health data?

Only if you connect your watch to an employer-provided health or wellness program and agree to share the data. Your employer does not have default access to your watch's health data. If you join a corporate wellness incentive program, you usually must sign a consent form that specifies what data is shared. Read that form carefully, and check whether the program uses a third-party data processor.

Does the watch maker store my ECG recordings?

Yes, if you use the ECG app on Apple Watch, the recording is stored in the Health app on your iPhone and in iCloud if you have Health data sync enabled. The watch screen itself shows the result, but the full waveform is saved on the phone and cloud. ECG results are classified as health data subject to the same privacy controls as your heart rate data.

What is the difference between health data and medical data from a privacy perspective?

Health data is information that tracks wellness and fitness, such as steps, sleep, and heart rate. Medical data usually refers to information used to diagnose, treat, or manage a condition. The FDA does not regulate general wellness products, but it does regulate software that functions as a medical device, such as the ECG app. For privacy purposes, both types are sensitive, but wellness data has fewer regulatory protections, so you should be more cautious about which apps you grant access.

If I sell my smartwatch, can the next owner see my health data?

No, if you properly unpair and reset the watch. Unpairing removes the watch from your phone and triggers a reset that erases the local data. You should always remove the watch from your account (using Find My on iPhone, or the Android settings) and then perform a factory reset before selling. Our guide on preparing a smartwatch for resale covers the exact steps.

Does a kids' smartwatch have stricter privacy rules than an adult watch?

Yes. In the US, the Children's Online Privacy Protection Act applies to online services directed at children under 13. It requires the service to get parental consent before collecting personal information, including health data. When you set up a children's watch, the maker must provide a clear notice and honor your choices about data use. You also have the right to review and delete your child's data. The Federal Trade Commission enforces the COPPA Rule. If you think a kids' watch does not comply, you can report it to the FTC.