YouTube thumbnail size: the official 2026 dimensions
YouTube's help page recommends a 16:9 video thumbnail of 3840 x 2160 pixels, with a minimum width of 640 pixels, uploaded as an image format such as JPG or PNG. Many guides still say 1280 x 720; that size is 16:9 and above the minimum, so it works, but it is not the largest size YouTube recommends. Shorts use 9:16 at 2160 x 3840.
The official numbers, side by side
| Standard video | Shorts | |
|---|---|---|
| Recommended resolution | 3840 x 2160 pixels | 2160 x 3840 pixels |
| Minimum | 640 pixels wide | 640 pixels tall |
| Aspect ratio | 16:9 | 9:16 |
| File type | Image formats such as JPG or PNG | |
| File size limit | Mobile upload: 2 MB for video thumbnails. Desktop upload: 50 MB for video, Shorts and podcast thumbnails. | |
YouTube's help page says your custom thumbnail should be as large as possible, because it is used as the preview image in the embedded player. That is why the recommended resolution is a large 4K-class frame rather than a small one.
Is 1280 x 720 still fine?
Yes, as a working size. 1280 x 720 is a 16:9 frame and it is well above the 640-pixel minimum width, so YouTube accepts it. It is also the figure many guides still list as the size, together with a flat 2 MB cap and GIF support. On 2026-10-04 YouTube's own page lists 3840 x 2160, names image formats such as JPG or PNG (it does not mention GIF), and gives a 2 MB cap only for uploads from mobile. When a guide and the help page disagree, follow the help page.
The practical choice: if you design in your own editor, export 16:9 at the largest size that stays under your upload limit. If you generate the thumbnail with a tool that outputs 1280 x 720 (ThumbnailMaker does), you are within the rules, but you are not at the largest size YouTube recommends.
Aspect ratio: 16:9 for videos, 9:16 for Shorts
Standard videos should use a 16:9 thumbnail and Shorts a 9:16 one. Podcast playlists use 1:1. Build to the right ratio from the start so nothing important is cropped. See the format and file size guide for the upload limits and the common reasons an upload fails, and the Shorts thumbnail size guide for the vertical rules.
Before you upload
Custom thumbnails need a verified account. Upload in YouTube Studio: Content, open the video, then Thumbnail, Upload file, Save. Changes can take a little while to appear.
Design for the smallest place it appears
A thumbnail is small in a feed and large on a watch page, so it has to read at both. Use a few large words, high contrast and one clear focal point. This is design advice, not a YouTube requirement.
Sources
- YouTube Help, "Add custom thumbnails on YouTube": https://support.google.com/youtube/answer/72431 (read 2026-10-04)
- Shopify, "YouTube thumbnail size": https://www.shopify.com/blog/youtube-thumbnail-size and TechSmith, "YouTube Thumbnail Sizes": https://www.techsmith.com/blog/youtube-thumbnail-sizes/ (read 2026-10-04, cited only to show which older figures other guides still list)