I edit the video on FCPX and dimension 1080 x 1920. However, when I upload the clip to snapchat they're distorted badly. What did I do wrong? Can anyone show me step by step of how I should set up my clip in FCPX and the exporting format as well. Thank you
Make certain you are exporting it to the same format, and not UP-SCALING it!
Take a look at the export settings, and try it on the lowest. Upload it and view it. Keep making slightly better formats until you reach the point it looks distorted.
It's kind of fun to do the impossible! -Walter Elias Disney