Combine FIT Files
Combine multiple FIT files into a single activity. Trim each file before stitching, drop overlapping segments, and download the merged result. Perfect for split recordings, multi-sport events, or sessions where your device stopped mid-activity.
Drag & drop your FIT files here
or click to browse — max 50 MB
When to Combine FIT Files
- Split recordings — Your device battery died mid-ride or you accidentally paused and started a new activity. Merge both files to recover the complete session.
- Multi-sport events — Transition sports recorded as separate files (swim + bike, or bike + run) can be joined into a single consolidated activity.
- Dual-device setups — If you wore a chest strap for heart rate and a GPS watch for positioning, merge the two files to get both data streams in one activity.
- Interrupted uploads — Some devices create multiple FIT files when a sync is interrupted. Merge them to restore the original continuous session.
The tool automatically detects timestamp order and aligns data channels. Overlapping timestamps between files are trimmed so the resulting activity plays back cleanly in Garmin Connect, TrainingPeaks, Strava, or any FIT-compatible platform.
FAQ
How do I combine two FIT files into one activity?
Upload your FIT files in the order you want them merged. The tool will detect timestamps and combine the data streams. If there are overlapping timestamps, you can choose to auto-trim the overlap.
Can I merge FIT files from different devices?
Yes. You can merge files from different devices, for example combining heart rate data from a chest strap with GPS data from a watch. The tool handles different data channels and sampling rates.
Why would I need to merge FIT files?
Common reasons include: your device stopped and restarted during an activity creating two files, you used multiple devices during a session, or you want to combine a multi-sport event into one file for Strava or Garmin Connect.