Private · Browser-based · Activity file diagnostics

Your activity file, understood.

View, diagnose, repair, recover and convert FIT activity files in one private browser workflow. Upload once; ActivityDoctor tells you what is healthy, what looks suspicious, and which repairs are safe.

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

Privacy by architecture

Activity files can contain precise location, timestamps, device identifiers and biometric data. Core FIT analysis runs in your browser using a Web Worker. The route view is a local vector drawing and does not request third-party map tiles.

ActivityDoctor is independent and is not affiliated with Garmin, Strava, Wahoo, COROS, Suunto or other device/platform vendors.
Analyzing FIT file…