FIT File Editor
Trim, cap, and adjust your FIT file data without installing software. Fix erroneous spikes, remove warmup sections, or crop your activity to the exact segment you need.
Drag & drop your FIT files here
or click to browse — max 50 MB
FAQ
Can I edit a FIT file without losing data?
Yes. This editor lets you trim, cap, and scale values while preserving all other data in the file. You can preview changes before exporting and use undo/redo to revert any edits.
How do I remove a warmup or cooldown from my FIT file?
Use the trim feature to set new start and end points. Drag the sliders on the activity timeline or enter exact timestamps. The trimmed file will contain only the data between your selected points.
How do I fix heart rate spikes in my FIT file?
Use the "Cap heart rate" feature to set a maximum value. Any readings above your cap will be clamped. This is useful for removing erroneous spikes caused by sensor dropouts or interference.
Is this FIT file editor free to use online?
Yes, completely free with no signup. The editor runs in your browser, has no file-size paywall, and exports edited FIT files that work directly with Garmin Connect, Strava, TrainingPeaks, and intervals.icu. There is no daily limit on the number of edits.
Is my FIT file uploaded to a server when I edit it?
No. The editor processes your file entirely in the browser using JavaScript. Nothing leaves your device — not the original file, not the edited version, not the timestamps. You can confirm this by opening DevTools → Network and watching for outbound requests while you edit. There are none.
Which devices and apps does this FIT editor support?
Any device that writes the standard FIT format: Garmin (Forerunner, Fenix, Edge, Epix), Wahoo ELEMNT, Suunto, Hammerhead Karoo, Coros, Polar Vantage, and Amazfit / Zepp watches with FIT export. Edited files import back into Garmin Connect, Strava, TrainingPeaks, intervals.icu, and Wahoo SYSTM without conversion.