Stamptivity
Free · No account · Runs locally

Combine activities into one file

Combine multiple GPX or FIT files into a single track and download as GPX.

Add at least 2 files to merge

Merge multiple GPX or FIT files into one

Merge stitches any number of GPX or FIT files into a single GPX track, ordered by timestamp with no gaps. It is the fix when a device split a ride across files, when you paused recording, or when you are joining stages of a multi-day route.

Drop all the files at once — order does not matter, they are sorted by GPS time — and download one continuous GPX, with heart rate, cadence, and elevation preserved where present.

Frequently asked questions

When should I merge activity files?+

When a GPS device paused or restarted mid-ride and made two files, when you exported separate morning and afternoon sessions, or when you are combining stages of a multi-day route into one track.

Can I merge FIT and GPX files together?+

Yes. Merge accepts any mix of .gpx and .fit in the same batch — no conversion needed. The output is always GPX, the most universally compatible format.

Does the order I add files matter?+

No. All points across all files are sorted by GPS timestamp, so you can drop them in any order, all at once.

Is my data preserved and kept private?+

Heart rate, cadence, elevation, and speed are preserved from the source files where available, and the merge happens entirely in your browser — nothing is uploaded.