What matters
YouTube Community Post dimensions at a glance
YouTube Community posts display images in the Community tab and in subscriber feeds. Square 1080×1080 gives the most predictable display across devices.
Community posts are a direct line to subscribers between uploads. Well-sized images make these posts look intentional rather than like random screenshots.
Very wide or tall images get cropped in the feed preview, potentially hiding the main subject or text behind a 'click to expand' interaction.