Upload videos Use the YouTube Android app to upload videos by recording a new video or selecting an existing one. Use the YouTube app Open the YouTube app . Tap Create Video. Select the file you’d like to upload and tap NEXT. If your video is 3 minutes or less and has a square or vertical aspect ratio, it will be uploaded as a Short. Learn more.
https://support.google.com/youtube/answer/57407?hl=en&co=GENIE.Platform%3DAndroid