FIT file guides

The problems that bring most people here, each with the fix. Every guide ends in the editor, which is free and keeps your file on your computer.

• How to Delete Part of a Strava Activity (Including the Middle)
  Strava only trims the start and end of an activity. Here is how to cut a section from the middle of a ride or run, keep the rest, and re-upload it cleanly.
• Garmin Died Mid-Ride or Mid-Run? How to Merge the Two Files Into One Activity
  Your watch or bike computer died partway and you started a second recording. Here is how to combine both FIT files into one continuous activity for Strava or Garmin Connect.
• FIT File Won't Upload to Strava or Garmin Connect: How to Fix It
  A FIT file that is rejected on upload is usually truncated, corrupt, or not an activity at all. Here is how to tell which, and how to repair it in your browser.
• Garmin Connect Says Duplicate Activity After Editing a FIT File: How to Fix It
  Edited a FIT file and Garmin Connect or Strava rejected the upload as a duplicate? Here is why it happens and the order of steps that gets the edited file accepted.
• How to Fix a Heart Rate Spike in a Garmin or Wahoo FIT File
  A heart rate of 220 for the first ten minutes is a dry strap, not your heart. Here is how to cap or smooth the spike in the file so your averages and training load are right.
• FIT vs GPX vs TCX: Which Activity File Format to Use
  The three formats every watch, bike computer, and training platform speak, what each one actually holds, and which one to export or upload for a given job.
• How to Edit a FIT File on a Mac (No Software to Install)
  Most FIT editing tools are Windows-only. Here is how to crop, fix, merge, and repair a FIT file on macOS in Safari or Chrome, with nothing to install and nothing uploaded.

Looking for a specific job? Crop a FIT file, Merge FIT files, Fix FIT file data, Change the device, Adjust the time, Change the sport, browse the guides, or read the FIT format reference.