TCX Running Data Visualizer: Dual Axis Plot | roddornorn- road/offroad, outdoor/indoor running. Simply, r'n

Upload and analyze your running workouts directly in your browser. This widget reads TCX files and extracts metrics like heart rate, speed, cadence, elevation, and calculated values such as pace and grade - two metrics can be plotted simultaneously across distance or time with dual y-axes.

All processing happens on your device, the workout data stays private. In the blog post - Dig deeper into your running data - you can find some useful details on how to use the widget.

Upload a .tcx file:

Select Metrics +

X axis: Choose the horizontal axis metric (Distance or Time).
Left Y axis: Primary metric to plot (required).
Right Y axis: Optional second metric with separate scale. Choose "None" to disable dual-axis mode.

X axis: Left Y axis: Right Y axis:

Value Cutoff +

Min/Max thresholds: Clamp metric values to a range. Values above max are reduced to max, values below min are increased to min. Points are not deleted, only adjusted. Leave empty for no cutoff. For Pace metrics, use MM:SS format (e.g., 4:30).

Left Y Cutoff: Right Y Cutoff:

Moving Average Smoothing +

Purpose: Reduce noise in metrics by smoothing with a moving average. Window size ranges from minimum (20m or 5s) to 50% of total x-axis range.
How it works: For each point, the metric value is replaced with the average of all points within the window. Applied before binning.
Min window: 20 meters for distance metrics, 5 seconds for time metrics. Set window to 0 to disable smoothing.

X-axis Smoothing Window (0 = no smoothing):

Data Binning +

Purpose: Reduce data point density to reveal trends (useful for long workouts).
X-axis binning: Divides the x-range into equal segments and aggregates points within each segment. Choose "Step" for discrete intervals or "Midpoint-to-Midpoint" for smooth trend visualization.
Y-axis binning: Compresses the y-value range into discrete levels. Points are clamped to nearest level (preserves x-positions).
Aggregation method: Mean (average), Median (middle value, robust to outliers), or Mode (most frequent value).
Set slider/input to 0 to disable binning for that axis.

X-axis Binning (0 = no binning):

Left Y-axis Binning (0 = no binning):

Right Y-axis Binning (0 = no binning):

Summary +

Workout metrics after all transformations:
- Total distance: sum of x-axis distance values
- Total moving time: sum of time intervals with speed > 0
- Total elapsed time: difference between max and min time values
- Mean metrics: average of selected Y-axis metric(s) after all transformations (cutoff, smoothing, binning)
- Pace: calculated directly from total distance divided by total elapsed or moving time, rather than averaged from samples, to minimize measurement error.