FIT File Viewer

Drop a .fit file here or click to choose one - workouts and rides Choose a .fit file

Your FTP in watts (optional)

The file is read in your browser with Garmin's official FIT SDK and is never uploaded. Enter your FTP to see power targets in both watts and % of FTP.

Workout Ride Other FIT file Workout Total time Steps # Step Type Duration Target Warm-up Work Recovery Cool-down Rest Interval Other No target Head-unit zone {zone} Repeat from step {toStep} - {times}× in total (≈ {watts}) (≈ {pct} FTP) Nothing here would trip a head unit: durations, targets and repeats look right. The ride looks complete. Error: Warning: Note: Same for steps {steps}. The whole workout lasts {hours} h, and a head unit would show it that way - the durations are probably stored in the wrong unit. Step {step} lasts {hours} h. That is almost certainly a duration written in the wrong unit. Step {step} has a target range but its target value is not set to 0, so a head unit may read it as a zone number instead of the range. Step {step} uses zone {zone} of the head unit itself, so the range depends on the zones set on the device. Step {step}: the lower target is above the upper one. Step {step}: a target of {value} is not realistic. Power targets are stored as % of FTP: the head unit turns them into watts with the FTP set on the device. The file declares {declared} steps but contains {actual}. The workout has no steps. Step {step} repeats a step that does not come before it, so the loop cannot run. The ride has no recorded samples. The file has no session summary, so apps will compute the totals themselves. The samples cover {recorded} s, but the file says the ride took {declared} s - part of the recording may be missing. The file checksum does not match: it may be truncated or edited. Garmin's decoder reported {count} error(s) while reading the file. This is not a FIT file. The file could not be read. The FIT decoder could not be loaded. Check your connection and try again. This FIT file is of type {type}. The viewer breaks down workouts and rides only. Reading the file… Start Elapsed time Distance Average power Normalized power Max power Average heart rate TSS Calories Records Laps

Export workouts that load right WattLog.PRO writes your planned workouts as FIT files with Garmin's own SDK, with targets in watts from your FTP, so your head unit shows exactly what the trainer would ride in ERG.

Open WattLog.PRO

What the viewer checks

A workout FIT file is a list of steps: how long each lasts, what to hold, and where to loop back for repeats. Small encoding mistakes stay invisible until you start the workout on the bike - a 45-minute step the head unit shows as 750 hours, or a power target it reads as a zone number. The viewer flags steps longer than six hours, targets without the custom-range marker, repeats that point nowhere and step counts that do not add up.

Targets are shown the way the FIT protocol stores them. A power value up to 1000 is a percentage of FTP, so the head unit applies the FTP set on the device; above 1000 it is watts plus 1000. Heart rate works the same way with an offset of 100. Enter your FTP and the viewer shows both units side by side.

Rides and other FIT files

Open a recorded ride and the viewer summarises the session: start, elapsed time, distance, average and normalized power, heart rate, TSS and the number of records. It also warns when the recorded samples do not cover the time the file claims, a common sign of a cut-off recording.

Files from Garmin Connect, Wahoo, Zwift, TrainingPeaks or WattLog.PRO all use the same protocol, so any of them can be checked. Other FIT file types, such as courses or device settings, are recognised and named but not broken down.

Frequently asked questions

Is my file uploaded anywhere?

No. The file is read with JavaScript in your browser and stays on your device. The page only downloads the decoder itself, Garmin's FIT SDK, from the npm package registry.

Why does my workout show the wrong power on my Garmin?

The two most common reasons are a target stored as a percentage of FTP while the head unit has a different FTP set, and a target marked as a zone instead of a custom range. The viewer shows which one your file uses. Setting the same FTP on the head unit as in your training app fixes the first.

How do I put a workout FIT file on my Garmin Edge?

Connect the Edge to a computer with a USB cable and copy the file into the Garmin/NewFiles folder. When you unplug it, the Edge imports the file and lists it with your workouts.