GPX Track Simplifier trims redundant GPS points from a recorded track using the classic Ramer-Douglas-Peucker (RDP) algorithm. Long recordings often log a point every second, producing huge files with far more detail than any map needs. This tool removes points that lie close to the straight line between their neighbours, shrinking the file while keeping the visible route shape intact — all in your browser, with nothing uploaded.
How it works
RDP works recursively on each track segment. Given the segment’s first and last points, it finds the intermediate point with the greatest perpendicular distance from the line connecting them. If that distance exceeds epsilon, the point is kept and the segment is split in two at that point, with the algorithm applied to each half. If no point exceeds epsilon, every intermediate point is discarded and only the endpoints remain.
Because GPS coordinates are in degrees, the tool converts them to metres before measuring distance. It uses a local equirectangular projection: longitude is scaled by cos(latitude) to account for meridian convergence, and both axes are multiplied by metres-per-degree. Perpendicular distance is then computed on that flat plane, making the epsilon comparison meaningful in real-world metres.
Tips and example
Start with an epsilon of around 5–10 metres for hiking or cycling tracks — that typically removes the majority of points with no visible change at normal zoom. Increase it for overview maps where fine wiggles do not matter, and decrease it for technical routes where every switchback counts. The endpoints of each segment are always preserved, so a closed loop stays closed. Try the sample track, then adjust epsilon and watch the retained-point count fall.