Wondering why your activity's elevation gain or elevation profile look different?
For devices without recognized barometric altimeters*, Strava uses your activity's GPS data to "look up" the elevation for each point you record. The elevation points are smoothed slightly to reduce noise then display as the activity's elevation gain.
Up until recently, we used a publicly available global elevation database to look up elevation. However, we were not able to control for the many errors in this database which could cause significant inaccuracies or inflations of an activity's elevation gain. You can read more about this former method in our article about elevation for your activity.
Now, we have a new elevation look-up service powered by data from the Strava community.
Each activity that is uploaded from a device with a barometric altimeter is used to build the Strava elevation basemap. Using this basemap to look up your elevation will provide a better elevation service because barometric altimeters are known to be more accurate than the public database. Not only will elevation be more accurate on Strava, but using the basemap will result in more consistent metrics between devices, both with or without a barometric altimeter.
If there is no basemap data available for all or part of your activity, we will use the former method with the public database. If you opt to correct your elevation after recording with a barometric altimeter, we will also use the basemap.
If you have any questions or feedback about your activity's elevation data, please send us examples and comments by filling this form.
*Our calculations have not changed for devices with barometric altimeters recognized by Strava. If Strava is using your device's barometric altimeter data, the label "Elevation(?)" will appear blue under your elevation gain stat on any activity page.