Add elevation to GPX files

Give every point in a GPX file the elevation of the ground beneath it, read from the USGS 3DEP lidar model. For tracks and routes in Wisconsin.

Why add elevation to a GPX file?

Many GPX files have no elevation at all: routes drawn in a planning app, tracks exported from some phones, files converted from other formats. Others have elevation recorded by a GPS receiver or barometer, which is noisy or drifts. Ground elevations improve:

• Route planning: total climb and descent you can trust.
• Training records: anything your app works out from elevation.
• Visualization: cleaner profiles and 3D route views.
• Analysis: real grades and steep sections.

How it works

1. Upload: open Elevate a File and, with a pass active, choose the GPX file (up to 50 MB, with all points inside a square 3.7 miles on a side).
2. Processing: every <trkpt>, <rtept> and <wpt> is sampled from the 3DEP model. An existing <ele> is replaced; where a point has none, one is added as the point’s first element, where the GPX schema expects it.
3. Download: the file comes back as yourfile_elevation.gpx.

A track point in the returned file looks like this (a point on the east side of the Blue Mounds, west of Madison; the time is illustrative):

<trkpt lat="43.02700" lon="-89.84100">
  <ele>451.5</ele>
  <time>2026-08-14T16:02:11Z</time>
</trkpt>

Values in the file are in meters, with one decimal, because the GPX 1.1 schema defines <ele> that way. GPS apps convert it to feet for display. Times, names, extensions such as heart rate and cadence, and the coordinates themselves are left as they were.

Supported file formats

The same tool adds elevation to:

• GPX: tracks, routes and waypoints (this page).
• KML: Google Earth placemarks, paths and polygons; see adding elevation to KML files.
• GeoJSON: any geometry, as a third coordinate; see adding elevation to GeoJSON files.
• CSV: tables with latitude and longitude columns; see adding elevation to CSV files.

Use cases

Hiking and backpacking

Add elevation to a route drawn in a planning app before a trip through the Kettle Moraine or along the bluffs of the Driftless Area, so your GPS unit shows a real profile.

Mountain biking

Give a recorded ride ground elevations to see the real climbs and descents of a loop in glacial hill country or the Northwoods.

Running and trail running

Replace watch altitude on runs in the Kettle Moraine and other forested trails, where GPS altitude is at its worst.

GPS track correction

If a device recorded poor elevation, replace it with ground values. See GPX elevation correction.

Data quality

Ground elevations come from the USGS 3D Elevation Program (3DEP) seamless bare-earth model, with elevations above NAVD 88. Source cells are 3.3 ft per pixel in the finest work units, with about 9.8 ft per pixel and 33 ft per pixel sources elsewhere. USGS elevation data is public domain. Lidar coverage and source dates vary across Wisconsin. Check your site against the USGS 3DEP work-unit index; an unavailable lookup means coverage is unknown. The file’s points are read from a grid of the model laid over the area they cover, at most 1,024 samples across its longest side: for a file that covers a small area the grid is as fine as the source, and for a file that spreads toward the 3.7 miles limit it is coarser. Each point is interpolated between the four nearest cells of that grid. Points outside Wisconsin, or where no elevation can be read, are left without a value. More from the USGS 3D Elevation Program and Wisconsin elevation resources.

Privacy

The file is sent to the server, processed and sent straight back. It is not stored.

Related guides

• GPX elevation correction
• Elevation profile generator
• Add elevation to KML files
• About the Elevate a File tool