YouTube source-checked spec
YouTube Video thumbnail image size
YouTube recommends 3840x2160 for video thumbnails, with a minimum width of 640 pixels and a 16:9 aspect ratio.
3840x2160 recommended for video thumbnails16:9reviewed 2026-09-28verified false
Source and note
Source: YouTube Help custom thumbnail guidance. Reviewed 2026-09-28.
This row describes uploader guidance, not Data API response sizes. The linked 1280x720 resize preset remains a smaller 16:9 option, not the current recommended resolution. Shorts and podcasts have separate guidance.
Platform image specs are compiled from official sources and source-checked by image cat. Platform rules can change, account types can differ, and acceptance is never guaranteed. If an official page does not state an effective date, effectiveDate is set to unknown and verified remains false.