Lodestar iconLodestar

Guides · Your Fitbit data

Your Fitbit app stopped syncing? Here's why

If an app that used to read your Fitbit data suddenly shows old numbers, won't sync or keeps asking you to sign in, the cause is probably not your tracker. The way outside apps get Fitbit data is changing.

What changed

For years, apps outside Fitbit read your data through the Fitbit Web API. Google is replacing it with the Google Health API. On Google's developer timeline, support for the old Fitbit Web API ended on September 30, 2026, and the old API is being switched off around the start of November 2026. After that, apps still using it can't get new data at all.

Sign-in is changing too. The old connection used a Fitbit login. The new one goes through your Google Account, so an app that has moved over will show you a Google sign-in screen and ask for your permission again. Your old connection doesn't carry across on its own.

What it looks like when an app hasn't moved yet

Your Fitbit itself keeps recording as normal, and your data is still in your account. The app just can't reach it through the old route.

What you can do

Questions to ask any app that reads your Fitbit data

A change like this is a good moment to check what you've connected. Some useful questions: Does the app need write access, or only read? Does it send your data to its own servers, and if so, what does it do with it? Can you delete everything it holds? Our guide to seeing your Fitbit data in more detail on iPhone goes through this in more depth.

How Lodestar fits in

Lodestar is an iPhone app built on the Google Health API from the start, so the switch doesn't affect it. You sign in with Google once and give it read-only access to your Fitbit data. It works out daily Sleep, Recovery, Effort, Stress and Energy scores on your phone, against your own baseline, and nothing is sent to us.

If an app you relied on for HRV or recovery scores has stopped working, Lodestar is free to try in beta.

Try it on your own Fitbit data

Lodestar is free in beta on iPhone. It reads your Fitbit data from Google Health, read-only, and works out every score on your phone.

Join the iPhone Beta

More about Lodestar

More guides

Lodestar is for general wellness and information only. It is not a medical device and does not diagnose, treat, cure or prevent any condition. Talk to a qualified health professional about any medical concern.