I want to edit a GPX file to reduce the density of the data points, eg reduce by 50% or 75% for example. I know I can edit the file by hand via a text editor but I wondered if there was a utility for MAC as diing it manually is very tedious, free is good !

I’ve done a little research online (eg ADZE) but wondered if anyone here had a better solution.

I’ve never tried it but in bikehike.co.uk there’s an option to reduce the number of track points which might do the trick but it’s to a set number of points rather than a percentage afaik.

I think that GPSBabel can do this.

There is a simplify option which should do what you want (although there are probably other options if not)
http://www.gpsbabel.org/htmldoc-1.3.6/filter_simplify.html

I’d look at GPSBabel. Works on pretty much any platform, with pretty much any GPS input file (GPX, KML, etc. for routes, tracks, waypoints etc.)

edit: must type faster 😉

upload to bikehike then fill yer boots.

There may be easier ways but I open the route with gpsmarengo and replot in a new tab of gpsmarengo with desired number of trackpoints then use gpsbabel to load back to my garmin edge hth

Thanks, the above looks good and I hadn’t come across those programmes – I’ll try then out

Or Garmin BaseCamp can do this. You can download it for free, there is a Mac version.

Bascamp – I could not find the option to save a reduced track file size, only for device download of routes

GPSBabel – I thin the simplify feature has been removed, linked documentation page says its an obsolete feature and I couldn’t find anything similar in the application

bikehike is the winner, it tells you how many track points you’ve got and you can define a smaller number for file output (download)

Thanks again everyone – FYI I wanted this so I can combine tracks files to create trail maps for myself as I ride different trails on different rides.

Which version of GPSBabel are you using?

I’ve got v0.2.22.0, and the simplify function is there. Click on the Filter button and simplify is halfway down the pop-up.

FYI next time.
Basecamp – right click on track -> advanced -> filter -> points.