Free up Fitbit storage

The Fitbit app (or Google Health, depending on version) caches sync leftovers, activity maps, and photos you attach. Steps, sleep, and workouts stay on your Fitbit account after you sign in. Local cache is the leftover. Music you put on a Fitbit watch lives on the watch, not in this phone app.

See how much space Fitbit is using

iPhone

Open the iPhone Settings app.
Tap General > iPhone Storage.
Tap Fitbit or Health if that is the current app name.

Android

Open your phone Settings > Apps (or Apps and notifications).
Tap Fitbit or Health.
Tap Storage or Storage and cache.

Years of GPS maps plus food photos can outgrow the app binary. There is no WhatsApp-style Free up Storage screen.

Activity photos

Open an exercise that has a photo.
Photos you snapped on this phone also sit in Camera Roll.
Delete the copy you do not need (in Fitbit, in Photos, or both).

The workout stays on the account if you only remove a picture. Sync first so the tracker has uploaded recent days.

Watch music and offline maps

Playlists you synced to a music-capable Fitbit watch use watch storage. Offline maps are not a documented Fitbit phone-app download. Remove watch music from the watch or Fitbit device settings if that is the large number, not from phone cache.

Clear Fitbit cache on Android

Open your phone Settings > Apps > Fitbit or Health.
Tap Storage or Storage and cache.
Tap Clear cache.

Google Health Help documents this for sync problems. Do not tap Clear storage / Clear data unless you mean to reset Fitbit on this phone. That signs you out. Cloud history stays. You may need to pair the tracker again.

iPhone does not offer a separate Fitbit cache button. Google Help treats uninstall and reinstall as the iPhone equivalent. Offload the app in iPhone Storage if the system total stays high.

Reinstall the app if storage is still high

If you already cleaned media and Fitbit still looks huge, a fresh install can clear leftover cache and temp files that are hard to reach by hand.

Synced steps, sleep, and workouts stay on your Fitbit account. Pair the tracker again after you sign in. Watch music stays on the watch until you remove it there.
Delete the app from your phone.
Restart your phone.
Install Fitbit again from the App Store or Google Play.
Sign in and restore from backup if the app offers it.

This often frees a lot of space. You may need to download some media again after restore.

What to do next

After Fitbit is lighter, check your photo library for duplicates and similar shots. That is what Dedupo is for.

More app guides: Free up app storage.