GPS Speedometer
A live speedometer and activity tracker in your browser: pick a mode (walk, run, cycle, drive, boat) and get speed or pace, per-km/mi splits, auto-paused moving time, distance and max — all computed on your device from the GPS stream, exportable as a GPX track, never uploaded.
Speed is computed on your device from GPS fixes; auto-pause freezes the clock when you stop. Nothing is transmitted — the recorded track exists only in this tab until you export it.
Accuracy: what GPS speed can and cannot tell you
GPS speed is derived from Doppler shift and position deltas; on a clear sky it is accurate to ±1–2 km/h at steady speed — comparable to a car's (deliberately optimistic) dashboard. Expect noise below walking pace, under tree cover, between tall buildings, or on a train (window seats help). Cycling, running, boating and road trips are the sweet spot. Tip for boats: tap the unit chip to switch to knots.
Activity modes, splits and auto-pause
Modes tune the tool to the activity: walk/run show pace (min/km or min/mi) with per-kilometre splits, cycle and drive show speed with higher jitter thresholds, boat switches to knots. Auto-pause freezes the clock when you stop (traffic lights, water breaks), so average speed reflects moving time. Everything still runs offline once the page is loaded — and the whole session exports as a GPX track for Strava-style apps or our file viewer.