A LITTLE CLARITY. BACK TO THE RIDE.
Help with FIT, GPX and TCX files.
A ride worth keeping. A file that needs a little work. Find the right tool, understand your recording and leave with a result you can review.
Start with what you want to change.
You do not need to know the internals of your file. Pick a task below, or inspect it first if you are unsure what was recorded.
Understand a recording
See the route, device, sensors and details your file actually contains.
Keep the right part
Remove an accidental start, a long stop or a section you do not want to share.
Put a ride back together
Join compatible recordings when one ride was saved in several files.
Check the climbing
Compare recorded heights with terrain, then review the corrected profile.
One edit or a whole tidy-up.
Use a standalone tool for one change. Open Studio when you want to combine supported edits in one working session, with history and undo.
- Open your original
Choose a FIT, GPX or TCX file from your device. Keep a backup; KADALTO works on a separate copy.
- Preview before you commit
Check the map, measurements and proposed changes. In Studio, apply a preview to update the current ride.
- Download and check
Export the verified result and review it before importing it elsewhere. Save before closing or reloading the tab.
The format matters. The contents matter more.
A file extension is a starting point. The available edits also depend on whether the file contains a recorded activity, a planned route, timestamps or sensor measurements.
The detailed recording
Common on cycling computers and watches. It can include GPS, sensors, laps, events and device details. Supported edits preserve relevant source fields; an edit is refused when those fields cannot be handled safely.
The route or track
Useful for exchanging GPS positions. A recorded track may include times and elevation; a planned route may not. Sensor readings depend on extensions. A time-based edit needs usable recorded timestamps.
The structured activity
Can hold activities, laps, GPS positions and fitness measurements. Supported operations depend on the activity structure and recorded channels. Inspect the file to see what is available.
The table of points
Supported tables with latitude and longitude can become GPX tracks. CSV is also useful for reviewing exported measurements. It does not carry every part of a FIT or TCX recording.
How to upload to Strava
- Download your finished FIT, GPX or TCX file.
- Open Strava’s file uploader
- Sign in, choose the downloaded file, then review and save the activity on Strava.
On a phone, select the file from Downloads or Files using Strava in your browser.
Use a recorded activity with timestamps. Strava may reject duplicates or files over 25 MB.
KADALTO does not upload the file automatically.
A clear next step when something stops.
My file will not open.
Check the accepted format and the 20 MiB input limit. A file can have the right extension and still be incomplete, malformed or contain an unsupported object. Try a fresh export from the recording device or its original app. Renaming the extension will not convert it.
Try Inspect firstThe map is missing, but I can see measurements.
Indoor recordings and files without GPS can still contain useful sensor data. If positions exist but the street background is unavailable, use the local route view or retry the map. No basemap can replace coordinates missing from the file.
Read about maps and GPSMy merged ride has an overlap or a time warning.
Check that all parts belong to the same ride and are in the right order. Review every join and any overlap warning. If the original timestamps are wrong, correct the affected file first instead of forcing an ambiguous merge.
Check ride timestampsThe elevation total is different after export.
Climbing totals depend on the height profile, smoothing and noise thresholds. Device totals and profile estimates are different measurements, and another platform may recalculate them. Compare the profiles and method, not only the final number.
Understand elevation gain differencesAn edit was refused or verification failed.
No successful single-file download is offered until the generated file passes verification. Read the error’s next step and expand technical details if needed. Retry after adjusting the settings, use another supported output, or keep the original. A failed edit is not permission to discard your source recording.
Get help with an errorA simple CSV starting point.
Use a header row with latitude and longitude in decimal degrees. Supported timestamp and elevation columns are optional. Use a decimal point in the data; column names are file syntax and stay in English.
latitude,longitude,timestamp,elevation
51.5000,-0.1200,2026-01-01T10:00:00Z,24
51.5005,-0.1195,2026-01-01T10:00:10Z,25The Z marks UTC. It is a file-format example, not the date style used elsewhere on the website.
Convert CSV to GPXYour file stays yours.
Ride files are processed in your browser, without a processing upload or an account. Online maps request viewed regions from the map provider. Terrain correction requests geographic height tiles through our server. Manual file edits do not need a terrain lookup.
Each input is limited to 20 MiB, and very large or complex rides can reach processing limits. Batch results are reported per file. Your working session is held in memory, so download completed work before closing or reloading the tab.