Free online FIT file editor

FIT File Editor fixes a ride or run in your browser, so you can send a clean copy to Strava, Garmin Connect, or wherever you log your training. It's free, and the file never gets uploaded.

What you can do

The whole activity sits on one timeline, like a video editor for your workout: the map on top, every data stream below, and your edits previewed live. Crop out a part you don't want, like a warm-up or the drive home you forgot to stop recording. Strava only lets you trim the start and end of a ride or run, so you need a tool like this to edit or cut something out of the middle. Drag across it, hit Cut, and the laps and totals sort themselves out.

Bad data is just as quick to clean up. Cap a heart rate spike from a dry strap, smooth a power dropout, or pull a wandering GPS point back onto the road. You can also change the device or sport, shift the start time, join two rides into one after a watch dies partway, or rescue a file that won't upload after a crash.

Common edits

Jump straight to what you want to do:

Building something with FIT files? Read the FIT format reference for developers and AI agents.

Works with your gear

Garmin, Wahoo, COROS, Suunto, Polar, Hammerhead, Zwift, Apple Watch through HealthFit, and anything else that writes a standard .FIT file.

What is a FIT file?

FIT stands for Flexible and Interoperable Data Transfer, the format Garmin built to pack a whole workout into one small file. It records your position, heart rate, power, cadence, and more a few times a second, plus laps and a summary, so it holds far more than a plain GPX track. Nearly every watch and bike computer writes it, and Strava, Garmin Connect, and TrainingPeaks all read it, which is how it became the common language for activity data.

FAQ

How do I cut out the middle of a ride or run?
Drop the file in, drag across the part you want gone, and hit Cut. Then export and re-upload.
Will Strava and Garmin Connect accept the edited file?
Yes. You get a valid FIT file with the totals recalculated. Delete the original upload first so it doesn't show up twice.
Does my file get uploaded?
No. It all happens on your computer, so the file never leaves the browser.
Can I merge two files after my watch died mid-ride?
Yes. Add both and they line up on one timeline, then export as a single activity.
Can I change the device, sport, or date on a FIT file?
Yes. Open the details panel to change the recording device, the sport, the activity name, or shift the start date and time.

Who made this

Hi, I'm Jason, an ultrarunner and triathlete. I built FIT File Editor because fixing a file used to mean a different single-purpose tool for every problem, and none of them showed you what you were changing. I wanted it to work the way a video editor does: the whole activity on one timeline, where you cut and fix what you need and export a clean file. That idea still drives every feature. Find me running in Central Park.

Related FIT file tools

A few other places to view, fix, or convert activity files, or read the full comparison of FIT file tools: