To transfer your activities from Endomondo to Strava you'll need to export individual activities from Endomondo and upload them to Strava from our upload page.
Go to an activity on Endomondo.
Above the activity and to the right of the activity map, hover over "More Options" and then click on "Export". Select GPX file to download (do not select .tcx as Strava does not accept the version of tcx that is currently being produced by Endomondo) and the file will be downloaded to your download folder.
Repeat step 2 for all activities you'd like to export and upload to Strava.
Log in to your account on Strava.
Click Upload from the top right of any page and then "From File" and browse to select the file(s) you downloaded. NOTE: files can be bulk uploaded to Strava in groups of up to 25.
Name your activities, and adjust the activity types as necessary.