How Health.app Prioritizes Data From Multiple Sources

Have you ever wondered how iOS and more specifically the Health app handles and prioritizes data from multiple sources?

I have an Apple Watch and an iPhone and both devices, if worn or carried at the same time, record the number of steps I take, among other data. Yet, the Health app reports the number of steps accurately and prevents duplicate data entry.

Until recently, I didn’t think about this because I naturally expected Apple to have figured out how to prevent duplicate data reported by both the iPhone and the Apple Watch.

Apple and Third-Party Devices

However, yesterday I got a Jawbone UP2 and the thought crossed my mind when the UP app asked for permission to read and write health data such as number of steps taken.

I’ll explain the reason behind buying a Jawbone UP2 in one of my next posts.

I talked to Apple to find out more about how Health prioritizes data from multiple sources and I was pointed to the following knowledge base article.

Turns out you can set the priority of your data sources for each attribute of your health data.