Stamptivity
Free · No account · Runs locally

Cut the bad part out

Switched activity mid-recording, a long stop, a GPS glitch — trim the ends or cut a section out of the middle of your GPX or FIT track, then export a clean file.

Two ways to cut

Keep this range trims from the ends — pick what to keep, everything outside it is dropped. Same as most GPS platforms' built-in crop tool.

Remove this range cuts a section out of the middle instead — for when the bad part isn't at the start or end, like switching activities without stopping the recording.

Cut a section out of a GPX or FIT file

Trim removes a range of points from a GPS track and re-exports a clean file — trim from the start or end the way Strava’s own crop tool does, or cut a section out of the middle for the cases that tool can’t handle, like switching from a run to a ride without stopping the recording, a long unplanned stop, or a GPS glitch that spikes your pace and elevation.

Drag the two handles over a time or distance axis, watch the route map and the before/after distance, duration, and average-speed preview update live, then export. Works with both GPX and FIT, unlike most competing browser-based GPX editors, which read GPX only.

Frequently asked questions

Can I cut a section out of the middle of my activity, not just the ends?+

Yes. Switch to "Remove this range" and drag the handles over the section you want gone — a GPS glitch, a long stop, or (for example) the last few kilometres of a run that was actually recorded on a bike. "Keep this range" covers the simpler start/end trim most GPS platforms already offer.

Does Trim work with FIT files, not just GPX?+

Yes. Trim reads FIT directly (from Garmin, Wahoo, COROS, and similar devices) and exports a GPX with the selected range removed — no need to convert first.

Will trimming change my average pace or speed for the rest of the activity?+

That is the point. Removing a bad section (wrong activity type, a long stop, a GPS glitch) recomputes the stats for what is left, so your average speed, pace, and distance reflect only the part of the activity you keep.

Is my GPS file uploaded anywhere?+

No. The file is parsed, cut, and re-exported entirely in your browser — nothing is uploaded to a server.