GPX Simplifier — Reduce Track Points

Field guide: GPX Simplifier

A watch logging every second turns a four-hour ride into 14,000 track points — and then a route site rejects the upload, a device with a 10,000-point ceiling truncates the course, or an embedded map grinds. Almost all of those points are redundant: on a straight road, the line through point A and point C passes within centimetres of point B. This tool applies the Douglas–Peucker algorithm — the standard line-simplification method in cartography — keeping every point that deviates from the simplified line by more than your chosen tolerance and discarding the rest.

Tolerance is in honest metres, computed perpendicular to the track (not in abstract degrees like many tools). At 5–10 m a typical recording loses 80–95% of its points with no visible change at any sane zoom; corners, switchbacks and turns survive because they genuinely deviate. Elevation and timestamps ride along on the points that remain, waypoints are untouched, and the before/after counts are shown so you can tune the slider. Processing is in-browser — your tracks never upload.

Field tips

• Start at 10 m: it's invisible on a map and usually clears device point limits with a single pass. Only go past 50 m for overview maps where the track is a thin line across a whole region.
• Simplification preserves shape, not signal: if you need every data point for power/pace analysis, keep the original for analytics and use the simplified copy for sharing and devices.
• Garmin course point limits (10,000 on many units) are about track points — a 25,000-point file at 10 m tolerance almost always fits with a huge margin.

Conversions run locally in your browser and follow the cited specifications. Always verify critical output in the target application; for survey-grade or legal data, confirm coordinate systems and datums with your GIS team.