What kinds of FIT corruption can be repaired?

FitFileLab handles invalid checksums, truncated files (e.g. a watch that ran out of battery mid-recording) and files containing unreadable blocks. It recovers every readable record and rebuilds a valid file.

Are my files uploaded to a server?

No. The whole repair runs locally in your browser. Your file never leaves your device.

Will the repaired file work in Garmin Connect and Strava?

Yes. The output is a standard FIT file with a valid checksum and a proper session/lap structure, ready to import.

Some data is still missing after repair. Why?

We can only recover what is still physically present in the file. If timestamps or GPS points were never written, they can't be reconstructed — but the rest of your activity is preserved.

Repair a corrupted FIT file

Recover a damaged FIT file that Garmin Connect or Strava refuses to import. FitFileLab reads everything still readable, rebuilds the file structure and gives you a clean .fit — all in your browser, nothing uploaded.

Drop a corrupted FIT file or click to browseFIT only — analyzed and repaired in your browser, never uploaded

How FIT repair works

1
Select your FIT file
Drop your corrupted .fit file onto the tool, or click to browse your device.
2
We analyze and repair it
FitFileLab reads everything still readable, rebuilds the file structure and recomputes missing summaries — entirely in your browser.
3
Download the repaired file
Get a clean .fit file ready to upload to Garmin Connect, Strava or any other app.

Frequently asked questions

What kinds of FIT corruption can be repaired?: FitFileLab handles invalid checksums, truncated files (e.g. a watch that ran out of battery mid-recording) and files containing unreadable blocks. It recovers every readable record and rebuilds a valid file.
Are my files uploaded to a server?: No. The whole repair runs locally in your browser. Your file never leaves your device.
Will the repaired file work in Garmin Connect and Strava?: Yes. The output is a standard FIT file with a valid checksum and a proper session/lap structure, ready to import.
Some data is still missing after repair. Why?: We can only recover what is still physically present in the file. If timestamps or GPS points were never written, they can't be reconstructed — but the rest of your activity is preserved.