gpxding (ding translates into thing in English) is a utility to minify GPX files by removing redundant information. Only (a reduced number of) track points and elevation (optional) information is retained, while all other excess information is discarded. File size will be drastically reduced, while still accurate and useful for route navigation.

The goal of gpxding is to have the smallest possible GPX file for route navigation.

Installation

Prerequisites

Libxml2 is a required package for gpxding and installation depends on the OS, e.g.

sudo apt install libxml2-dev
or
sudo yum install libxml2-dev
or
...

Build

make
sudo make install

Usage

gpxding version v0.0.5
Usage: gpxding [OPTIONS] [FILE ...]
  -d    number of digits (default 5)
  -e    omit elevation info
  -h    show this help
  -m    use minimal <gpx> (not compatible with all apps/devices)
  -n    remove nearby points (default disabled)
  -p    precision in meters (default 2.0 m)
  -q    quiet
  -s    remove spikes (default disabled)
  -t    split gpx file into individual tracks

Example

$ gpxding *.gpx
Andorra_la_Vella_Quillan.gpx => Andorra_la_Vella_Quillan.gpx.gpx
   18761 =>     2087 (11.12%) trackpoints
 5450286 =>   122161 (2.24%) bytes
Cierp_Andorra_la_Vella.gpx => Cierp_Andorra_la_Vella.gpx.gpx
   30443 =>     3054 (10.03%) trackpoints
 8839475 =>   177989 (2.01%) bytes

Features

• typically a GPX file will be reduced to about 10% of the original size, without losing relevant information for navigation
• reduce the number of track points using Ramer-Douglas-Peucker algorithm
• reduce longitude/latitude to a sensible amount of digits (preserving relevant precision), e.g. 14.9999997348 becomes 15.
• round elevation to the nearest meter (default) or omit it completely
• deduplicate nearby points, e.g. a recording wasn't stopped during a time-out
• reducing noise/spikes
• split multi track GPX files into multiple single track files
• very, very fast (e.g. much faster than gpsbabel)
• process multiple files with a single command (wildcard support)
• support for GPX files of unlimited sizes and number of track points (limited only by the amount of available memory)

Compatibility

• Bryton Active
• Garmin Connect (do not use "-m" option)
• GPS Visualizer
• gpx.studio
• Strava
• Suunto App
• and many others

Caveats

• In case of a GPX file with multiple tracks, all tracks will be reduced in size and merged into one track. However, a GPX file with multiple tracks can be split beforehand with the -t option.