# Fitbit, Google Health, and What's Next

If you use TrendWeight with a Fitbit account, there's a change coming that you should know about.

tldr: Google is retiring the API that TrendWeight uses to read weight data from Fitbit, and once it's gone, TrendWeight won't be able to sync from Fitbit anymore. And it's kind of gone already for new weights.

### What's happening

Google has folded Fitbit into Google Health. As part of that, they're shutting down the old Fitbit Web API — the one TrendWeight has always used to pull your weight from Fitbit. It goes away completely in September 2026, and once it does, the Fitbit connection stops working.

As far as I can tell, Fitbit has already stopped syncing new weight data to TrendWeight. You can still connect an account to get historical data, but new readings just aren't coming through anymore.

### The new API, and the catch

Google offers a replacement for the old API called the Google Health API. Access to is available to two groups:

*   If you want to use it for yourself or you have 100 users or fewer, you can get in with the and simply ask each user for their permission to download their data.
    
*   If you have more than 100 users, you have to pass Google's verification plus a third-party security audit, redone every year, because weight readings count as sensitive health data.
    

To be fair to Google, that's reasonable. Google Health holds a lot of personal information, and being picky about who gets access to it on behalf of their users is a good thing. But that second tier is built for companies — the kind that have compliance departments and are used to paying for security audits as a normal cost of doing business.

### Why I'm not doing it

TrendWeight has well more than 100 people connected through Fitbit, so the personal/small-project tier isn't an option. That leaves the company tier: an annual third-party audit and all the process around it.

The full-scale approval process assumes you're a real company, but TrendWeight is a free project I run in my spare time. Taking on a recurring audit process — with the complexity and the nontrivial cost that comes with it — isn't something I'm interested in doing for a hobby project. So TrendWeight won't be supporting Google Health API, at least directly (see more below).

### Your data isn't going anywhere

None of the Fitbit data you've already collected is affected. Everything that's already in TrendWeight stays in your charts exactly as it is. Nothing gets deleted, and TrendWeight itself isn't going anywhere. This only changes how new data comes in — not the history you've already built up.

One small caveat on that, though. Historically you've always been able to disconnect your Fitbit account and then later connect it to a new Trendweight account later to redownload your historical data. That won't be possible soon. That means two things:

1.  Make sure you use an email address with TrendWeight that you won't lose access to. This is the most common reason people end up needing to create a new TrendWeight account and re-attach old Fitbit accounts. You can change your email address or add multiple backup emails addresses on the [Account Page](https://accounts.trendweight.com/user).
    
2.  Make sure you keep a safe copy of your Fitbit data somewhere other than Trendweight (in case something goes wrong). You can download it from the [Download Page](https://trendweight.com/download).
    

### What's next

Here's what I'm working on so you have options:

*   **Withings still works**, and it's not caught up in any of this. If you want automatic syncing from a scale, Withings is fully supported today.
    
*   **A manual weight log is coming.** If you don't want to buy a new scale, I'm adding a way to type your weight in directly, quickly and easily each day. This way you can keep your trend going without any scale connection at all. It's close to being done, and I'll post about it when it's ready.
    
*   **A personal API is coming too.** That 100-user limit actually works in an individual's favor — As an individual Google Health user, you can get your own Google Health API access without the audit or review process. So I'm planning to publish a documented TrendWeight API that more technical users can use to wire up their own integration and push their data in. This one's for people comfortable with a bit of code, and I'll share details once it's ready.
    

### Sorry about the disruption

Some of you have used the Fitbit connection for years, and I'm sorry it's going away. It's not a change I went looking for. I'd rather tell you what's coming now than have it quietly stop working one day with no explanation. I'll keep posting here as the weight log and the API come together.

As always, if you have questions, reach out at erv@ewal.net.