Fitbit API vs Health Connect and HealthKit: Why Direct Integration Matters

Fitbit is one of the most widely used fitness trackers with over 120 million users worldwide. The device can be connected to both Android and Apple phones, creating a dilemma for developers:  connect directly to the Fitbit API or route data through platform aggregators like Apple HealthKit and Google Health Connect.

While aggregator platforms may appear convenient, they introduce major limitations, especially around data completeness, accuracy, and platform support.

‍Spike Wearables API solves this dilemma by providing direct Fitbit API integration alongside 500+ other devices through a single, unified platform. This eliminates the engineering overhead and long-term maintenance involved in managing multiple wearable integrations in-house.

Why do workout and health apps need direct Fitbit API integration?

Whether you're building a fitness app, sleep tracking platform, weight-loss program, or another wellness app, your users expect their Fitbit data to sync accurately and instantly.

Fitbit tracks granular metrics, but when this data flows through Google Health Connect or Apple HealthKit, several issues occur:

• Data gets mapped inconsistently across platforms
• Latency increases because syncing depends on OS-level restrictions
• You lose the Fitbit-specific proprietary metrics that users expect to see
• Apple HealthKit sync doesn’t exist without third-party apps

Spike Wearables API connects directly to the Fitbit API, giving you complete access to Fitbit’s health data without intermediaries or data loss while also eliminating the technical complexity of managing the integration yourself.

5 reasons direct Fitbit API integration via Spike outperforms Health Connect and HealthKit 

1. Complete Fitbit data access

Apple HealthKit and Google Health Connect only support a limited subset of Fitbit data. Many of Fitbit’s unique metrics simply don’t appear through aggregators.

Direct Fitbit API integration through Spike gives you complete access to Fitbit's proprietary metrics, including:

• Intraday metrics: Minute-by-minute heart rate tracking, steps, distance, calories burned, HRV (RMSSD), breathing rate with min/max values, SpO2 with min/max values, body temperature variations, ECG voltage, and body fat percentage tracking.
• Daily summaries: Active and basal calorie burn, steps, floors climbed, resting heart rate, active duration, VO2 max, and sleep skin temperature deviation.
• Sleep analysis: Total sleep duration broken down into deep, light, REM, and awake stages, nap duration, bedtime duration, sleep latency, wakeup latency, sleep interruptions, and breathing rate during sleep.
• Workout data: Activity-specific metrics including distance (walking, cycling, swimming, wheelchair), heart rate with min/max values, speed with min/max, elevation with min/max, and GPS coordinates for outdoor activities.

Spike Wearables API retrieves this data directly from Fitbit's servers with up to historical data backfilling and event deduplication.

2. One integration across all platforms

Apple HealthKit only works on iOS devices. Google Health Connect requires Android 14 or newer, and some devices don't support it at all. Building separate integrations for each platform multiplies your engineering overhead and creates inconsistent user experiences.

With the Spike Wearables API, you write one Fitbit data integration, and we take care of the rest.

3. Event-driven webhook notifications

Spike Wearables API supports event-driven webhook notifications. The moment users sync their Fitbit device, your backend receives updates with the latest data. On the other hand, Google Health Connect and Apple HealthKit rely on scheduled updates and background restrictions.

For even faster data access, Spike offers local SDK integration, so your app can retrieve Fitbit data directly from the device the moment users open your application. 

OuiLive, a corporate wellness platform, switched to Spike's SDK integration after webhook delays flooded their support team with tickets. "Our users work; they want to see their data right now," explains Antoine Delport, CPO of OuiLive. "If they don't see it, they freak out and write one-star reviews." After implementing Spike's local SDK, OuiLive reduced support tickets by 40% and improved user satisfaction.

With Spike, you can build responsive, low-latency features like a dashboard or connect it to Spike MCP to build personalized chatbots or AI fitness coaches. 

4. Add several devices with a single integration

If you want to support Fitbit, Garmin, Apple Watch, Oura, and Whoop through aggregators, you'll need to handle multiple integration paths with different data formats.

Spike Wearables API provides direct Fitbit integration, including the ones mentioned above and other 500 devices, reducing engineering overhead and enabling you to serve a wider user base. 

5. Reducing maintenance costs

Building Fitbit integration in-house involves managing API updates and custom logic. If you are integrating with the Spike API, we will take care of this as well as assign a dedicated implementation engineer to help with the initial setup.

We had instances where our clients reduced their support tickets by 40% after switching to Spike API from a competitor provider. 

Simplify your Fitbit integration

Adding Fitbit integration doesn't have to be complex. With the Spike Wearables API, you can connect to Fitbit and 500+ other wearable devices through a single, unified platform without building and managing separate logics. 

Spike handles the technical complexity so you can focus on core app features that differentiate your product.

‍Schedule a personalized demo to discuss your specific needs and see how Spike Wearables API can accelerate your development timeline while reducing long-term maintenance costs.