Debrief
no file loaded

Drop a .gpx, .fit or .zip file to read the run

Add two or three from the same course to compare them.

Your file is read here in the browser and never uploaded. Looking up past weather is optional, per run, and sends only a rounded location and the date.

Garmin Connect → activity → ⚙ → Export GPX, or Export Original for the zipped .fit

Runs compared

Time gained and lost

Pace

by course position

Split by split

The run

route trace
elevation profile

Kilometre splits

Heart rate

Time in zone

Pace

grade-adjusted overlaid

Cadence

Elevation

Terrain spread

distance by gradient

How it held together

pace and heart rate, split by split

Readouts

Your numbers

changes recalculate everything

Gradient-adjusted pace and the energy estimate use Minetti's cost-of-running curve, so steep ground is priced properly rather than ignored. Decoupling compares speed-per-beat in the first half of the run against the second — under about 5% is the usual marker of an aerobically sound effort at steady intensity, and it only means anything on a run you held at one intensity throughout. Threshold-based zones follow the Friel percentages. Every number here comes from the file you loaded, so it inherits whatever your watch's GPS and optical sensor got wrong. Weather, where you ask for it, comes from Open-Meteo reanalysis under CC BY 4.0 — a 9 km model grid rather than a reading from your street.