FIT File Repair
This is planned, not available yet: a tool to fix corrupted or truncated Garmin FIT files, the kind that fail to upload to Strava or Garmin Connect with an unhelpful error. We'd rather tell you that plainly than ship something that silently loses your data.
Your file never leaves your device.
Parsing, trimming, merging, and exporting all happen locally in your browser with JavaScript. GPXFIT never uploads your GPS coordinates to a server.
What works today
- The File Inspector attempts to decode the FIT file with Garmin's official FIT SDK and reports an error if the integrity check or decoding fails. For a file that opens, it shows the detected format, file size, activity name when present, segment count, start and end times, and track statistics. It doesn't diagnose the exact cause of a failure.
- If a FIT file does decode, you can already export its GPS track as GPX or TCX from the Inspector as a workaround.
What's still missing
- Repairing a truncated file (recovering a valid file when the recording cut off mid-write, a common failure after a low battery or crash).
- Rewriting a corrected FIT file with a valid CRC and header — GPXFIT can currently read FIT but not write it.
- Recovering partial data from files that fail the integrity check entirely.
Why this is hard
FIT is a binary, checksummed format. A trustworthy repair tool needs to distinguish between merely-truncated data (recoverable) and genuinely corrupted data (not safely recoverable) without silently fabricating GPS points. We'd rather ship this once it's reliable than rush a version that produces plausible-looking but wrong data.
Have a corrupted FIT file you'd like us to test against once this ships? Check back here — this page will be updated as the tool progresses.