HealthKit vs Health Connect for Developers
HealthKit vs Health Connect is rarely a choice: apps on iOS and Android integrate both. They share on-device, permissioned storage and privacy models but differ in APIs and data types. Build one health-data abstraction, add two native bridges and normalize to FHIR before the backend.
Quick answer
Cross-platform app → integrate both. Same concept, different APIs and data types. Abstract health data in your app; implement HealthKit and Health Connect underneath.
Decision table at a glance
| Criterion | HealthKit | Health Connect |
|---|---|---|
| Platform | iOS / watchOS | Android |
| Data location | On-device (Health app) | On-device (Health Connect) |
| Permission model | Per-data-type consent | Per-data-type consent |
| Wearable access | Apple Watch (ECG, activity) | Wear OS / partner devices |
| Maturity | Long-established | Newer (replaced Google Fit role) |
| Language / SDK | Swift / Objective-C | Kotlin / Java |
What they are
What is HealthKit
HealthKit is Apple's framework for health and fitness data on iOS and watchOS. Data lives on-device in the Health app, access is permissioned per type, and it's the gateway to Apple Watch metrics such as heart rate, ECG and activity. It's mature and widely adopted.
What is Health Connect
Health Connect is Android's on-device platform for sharing health and fitness data across apps, superseding the older Google Fit APIs. As with HealthKit, data stays local and permissioned per type, and other Android health apps and wearables read and write through it.
Key differences
Same philosophy, different plumbing
HealthKit and Health Connect both keep health data on-device, require per-type user permission and act as the platform's central health hub. Your consent UX and data handling can share one design, but the SDKs, languages (Swift vs Kotlin) and API shapes are separate implementations.
Data types overlap but don't match exactly
Steps, heart rate, sleep and workouts exist on both, but exact types, units and metadata differ, and each platform has signals the other lacks, such as Apple Watch ECG. Build an explicit mapping table to one internal model rather than assuming types map 1:1.
Wearable ecosystems diverge
HealthKit is the pipe to Apple Watch's rich sensor data. Health Connect aggregates from Wear OS and partner apps/devices. If specific wearable signals matter to your product, verify which platform actually surfaces them: this often drives more of the design than the frameworks themselves.
Normalize before the backend
Whatever you pull from either framework, normalize it, ideally to FHIR resources (Observation, etc.), before it reaches your server. That keeps your backend platform-agnostic, simplifies analytics, and makes clinical/EHR integration downstream far easier than storing raw HealthKit and Health Connect payloads.
When to use each
When to use Apple HealthKit
- You're building for iPhone/Apple Watch users and need on-device health data.
- You need Apple Watch-specific signals (ECG, AFib, workout, activity rings).
- Your users live in the Apple ecosystem and expect Health app integration.
- You're reading/writing standard health data types with per-type consent.
When to use Android Health Connect
- You're building for Android users and need on-device health/fitness data.
- You want a single Android hub that aggregates data from other health apps and devices.
- You're migrating off legacy Google Fit APIs to the current platform.
- You need standard health data types with granular, per-type permissions on Android.
Building one app across both
Define a platform-agnostic health-data interface in your app's domain layer, covering the data types, permissions and sync operations your product needs. Then implement two adapters beneath it, one for HealthKit on iOS and one for Health Connect on Android.
Centralize data-type mapping and unit conversions in one place, and test them against real device data early, since units, timezones and sample metadata cause most bugs. Send normalized, FHIR-shaped data to the backend so server logic stays identical on both platforms.
Frequently Asked Questions
Not sure which fits your build?
Tell us about your product, integration targets, and timeline. We'll map the trade-offs to your context and recommend the path that gets you to a compliant launch fastest.