The Perfect YouTube Video Size for 2020: Dimensions, Resolution, and Aspect Ratio | Distance Learning, mLearning, Digital Education, Technology | Scoop.it
From learn.g2.com - January 30, 2020 3:19 AM
The recommended YouTube video size for 2020 ranges from 2160p (3840x2160 pixels) for the best resolution to 280p (426 x 240 pixels) for the lowest accepted video quality. For HD videos, use 720p, the minimum resolution for HD videos, or 1080p, the maximum resolution for HD videos on YouTube.

Via Peter Mellow