Swim HR Merger
Replace Garmin wrist HR with Polar chest strap data.
All processing runs locally in your browser.
Garmin Swim FIT
Drop .fit file or click to browse
Polar HR TCX
Drop .tcx file or click to browse
Select both files to merge
Processing…
Heart Rate & Pace Comparison
Verify HR alignment — dips should match rest periods (amber bands)
Original HR (Garmin)
Merged HR (Polar)
Pace /100m
Rest
Fine-tune offset:
+0.0s
Re-merge
Merge Complete
Avg HR
—
Max HR
—
Coverage
—
Download Merged FIT