Private · Browser-based · Activity file diagnostics

FIT File Viewer

Open a Garmin-compatible FIT activity directly in your browser. Inspect route, activity statistics and sensor charts without sending the workout file to a server.

Drop your .FIT file here

Analysis runs locally in a Web Worker. Your workout file is not uploaded.

No upload No account Browser-only processing

activity.fit

Recovery confidence
Sport
Distance
Duration
Start

FIT health report

Activity stats

Average heart rate

Max heart rate

Average cadence

Average power

Private route map

Vector-only track visualization. No map tiles or GPS coordinates are requested from a third-party map service.

Recovery estimate

Repair & recovery options

Detected anomalies

Activity record sample

The interface downsamples very large activities for display. Repair logic works from the complete local file.

#TimeHRkm/hAltitudeCadencePower

What the FIT viewer shows

ActivityDoctor decodes common Activity messages and presents GPS, timestamps, heart rate, speed, elevation, cadence and power when those streams exist in the source file. Large files are downsampled only for visual display; the original stays unchanged.

Does this upload my route?

No. The FIT parser runs locally, and the route is rendered as a private vector track rather than fetching third-party map tiles.

Analyzing FIT file…