Sports & Fitness — entry 009 of 34
Fitbit
The Fitbit Web API exposes over 20 million active users' activity, sleep, heart rate, and body-composition data via OAuth 2.0-authorized REST endpoints returning JSON, free to register for and use within Fitbit's published per-user rate limit. Its own developer portal now carries a live deprecation notice: the legacy Web API is being retired in September 2026 in favor of a new Google Health Connect-based infrastructure, so integrations built today should plan for that migration. Access still requires each end user to grant consent through Fitbit's OAuth flow -- there is no app-level or service-account key.
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<a href="https://greatapis.com/api/fitbit/"><img src="https://greatapis.com/badge/fitbit.svg" alt="Scored 71 on greatapis.com"></a>Auth quickstart
- Register an app / run the OAuth flow to obtain a bearer token.
- Send it as an Authorization header
Authorization: Bearer <token>
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.