SMARTFIT BY TOOLMITRAA
Online FIT File Editor for Cycling, Running and GPS Activities
SmartFIT lets you inspect and edit FIT activity data while preserving valid distance, laps and sensor records. Use quick fixes or advanced range editing, then validate and export a new FIT file.
Edit activity data without rebuilding everything blindly
SmartFIT separates recorded data from generated or estimated data and can preserve the original FIT structure for compatible edits.
Time shifts, date changes and supported record-field edits can be applied while FIT integrity and summary consistency are checked.
- Change activity date, start time and timezone
- Edit heart rate, cadence, power, speed, temperature and altitude
- Repair GPS spikes and distance anomalies
- Preserve sensor-only records during GPS dropouts
- Inspect laps, sessions, device and sensor information
Built for real-world FIT problems
Older activity files can contain GPS dropouts, invalid sentinels, distance resets or manufacturer-specific messages. SmartFIT runs health checks before export so obvious corruption is not silently converted into a new error.
Frequently asked questions
Can I shift the time of a FIT file?
Yes. SmartFIT can shift timestamps by seconds, minutes, hours or days, or set a new start date and time.
Can I change heart rate or power data?
Yes. Supported streams can be set, added to, scaled, smoothed or filled over selected ranges.
Does SmartFIT preserve unknown FIT fields?
Preserve Original mode keeps unsupported or proprietary message bytes when the requested edit is structurally compatible.
More SmartFIT tools
FIT Tools Suite · FIT File Editor · FIT File Repair · Smart FIT Generator · Cycling Activity Generator · Running Activity Generator · Cycling Route Builder · GPX to FIT · FIT Converter · Activity Analyzer · Activity Library · Athlete Twin · Personal Heatmap