Merge, repair, and convert your workout files
Combine FIT, GPX and TCX recordings into one clean activity, pick which device provides each data stream, and download a file Strava and Garmin will accept — with a health check on every file and a totals reconciliation on every output.
Drop your FIT, GPX or TCX files here — or tap to choose files
Free plan: up to 2 files, 5 MB each — no account needed to try. Files are deleted after 24 hours.
No signup needed on the free plan · 3 merges a month · GPX/TCX export free, FIT export on paid plans · Your files are deleted after 24 hours · See a worked example
Stream-by-stream merging
Recorded the same ride twice — GPS and power on the bike computer, heart rate and cadence on the watch? FitMerge aligns the overlapping recordings and lets you choose the source file for each stream separately: GPS, elevation, heart rate, cadence, power and temperature. One activity, the best data from every device.
Repair, with a report
A battery dies mid-ride and the FIT file will not upload anywhere. FitMerge diagnoses truncated files, CRC errors and missing session records, repairs what can be repaired, and gives you a repair report that says exactly what was wrong and what was changed. Nothing is fixed silently.
Totals that reconcile
Every output comes with a reconciliation: point count, distance, duration and the coverage of each data stream, checked against the input files. If a stream lost points in the merge, the numbers show it — so you can trust the file before it becomes your only copy of the activity.
How it works
- Upload and health check — drop in FIT, GPX or TCX files and see, for each one, its point count, time range, which data streams it carries, and any damage we can diagnose.
- Choose a merge mode — stitch segments together in time order, or merge overlapping recordings stream by stream, picking the source device for each stream.
- Repair, if a file is damaged — truncated endings, CRC errors and missing session records are diagnosed and repaired where possible, with a written report.
- Download and reconcile — export GPX or TCX free, or FIT on paid plans, and check the totals reconciliation against your inputs.
Built for two-device athletes
Long rides and races get recorded in pieces: a paused computer, a swapped battery, a watch that kept going. Stitching segments, combining devices, and saving your usual device combination as a stream profile (Pro) is what paid plans are for — see pricing.
Your activities stay yours
Files are processed on our server so repairs and merges actually finish. Uploads are stored only so you can review and download your results, and they are deleted automatically after 24 hours — sooner if you delete them yourself. Details in the privacy policy.