Elevation data are downloaded from the internet, so in order for this process to complete you need to have an internet connection in your device. Before the actual process of adding elevation data into a track we strongly recommend you create a copy of a file that contains this track if you also want this new elevation data to overwrite the original elevation data in the file.

Below are steps describing how to add elevation data to a track in GPX Viewer PRO:

1. Open left main menu.
2. Tap on Track/route info button.
3. In Track/route info screen tap on … button and from menu select Add elevation data.
4. If the track already contains elevation data, GPX Viewer PRO will show you a dialog if you want to overwrite this elevation data with new elevation data from the internet. If you want this, then tap on the button Yes in the dialog.
5. After a while, (adding elevation data can take up to 1 minute, but it depends on how many tracks points the track contains and where it is located) elevation data will be added and GPX Viewer PRO will show you a dialog if you want to overwrite elevation data in a file which contains this track.
6. We strongly recommend you create a copy of a file that contains this track if something went wrong in the process or if you won't satisfy with elevation data precision. If you have done so, you can tap on the button Yes in this dialog.

Below is a video showing the instructions above: