Checked against the source
YouTube Shorts cover size
Short answer
YouTube Help gives Shorts thumbnails a resolution of 2160 × 3840 px, a minimum height of 640 px and a 9:16 aspect ratio, as JPG or PNG up to 50 MB from a computer. Custom Shorts thumbnails can only be added in YouTube Studio on a computer, and your account must be verified.
Key takeaways
- YouTube recommends 2160 × 3840 px for Shorts, with a minimum height of 640 px and an aspect ratio of 9:16. 2160 / 3840 is exactly 0.5625, which is 9:16.
- Custom Shorts thumbnails are only available in YouTube Studio on a computer, and your account must be verified to use them.
- The size limit YouTube states for Shorts thumbnails is 50 MB, from a desktop. The 2 MB mobile figure on its page is for video thumbnails, not Shorts.
- Vertical videos with 16:9 custom thumbnails are replaced by an auto-generated 4:5 thumbnail on the home, explore and subscription pages. The custom thumbnail still appears on the watch feed, watch history and non-mobile platforms.
- File types are image formats such as JPG or PNG.
The size
| What | Value |
|---|---|
| Width | 2160 px |
| Height | 3840 px |
| Aspect ratio | 9:16 |
What the platform publishes
| What | Published value |
|---|---|
| Recommended | 2160 × 3840 px (9:16) |
| Minimum | 640 px tall |
| File types | Image formats such as JPG or PNG |
| File size limit | 50 MB from a desktop. Custom Shorts thumbnails can only be added in YouTube Studio on a computer, and the account must be verified |
Source: YouTube Help: Add custom thumbnails (checked 2026-10-05)
Resize it now
Scales and center-crops any image to exactly 2160 x 3840 px, in your browser. Nothing is uploaded, there is no file size cap and no daily limit.
Batch is unlimited and free - every image is processed on your device, so there is no queue and no daily cap.
What YouTube publishes for Shorts thumbnails
The custom thumbnails help page treats video and Shorts thumbnails together, with separate lines for each. Under image size and resolution it says a thumbnail should have a resolution of 3840 × 2160 pixels for videos and 2160 × 3840 for Shorts, with a minimum width of 640 pixels for videos and a minimum height of 640 pixels for Shorts.
| What | Published value for Shorts |
|---|---|
| Resolution | 2160 × 3840 px |
| Minimum | 640 px tall |
| Aspect ratio | 9:16 (try to upload at this ratio) |
| File types | Image formats such as JPG or PNG |
| File size | Desktop: 50 MB for video, Shorts and podcast thumbnails |
| Where to add it | YouTube Studio on a computer only |
| Account requirement | Your account must be verified |
Add custom video thumbnails, Shorts lines, read 2026-10-09.
Which file size limit applies to Shorts
The same page lists mobile and desktop limits side by side. For mobile it gives 2 MB for video thumbnails or 10 MB for podcasts, and for desktop 50 MB for video, Shorts and podcast thumbnails. Shorts do not appear in the mobile line, and the page says custom Shorts thumbnails can only be added on a computer, so the 50 MB desktop figure is the one that applies.
The 4:5 swap, and why the cover shape matters
YouTube states that vertical videos with 16:9 custom thumbnails will be replaced by an auto-generated 4:5 thumbnail on the home, explore and subscription pages. The custom thumbnail still appears on the watch feed, the watch history and non-mobile platforms.
The practical point is that a 16:9 cover on a Short is not used in the places where most people browse. Uploading a 9:16 file avoids the replacement. Computed: a 9:16 frame at 2160 × 3840 px is 8,294,400 pixels, about 8.3 megapixels.
Sharpness at the smallest allowed size
The floor is 640 px tall. At 9:16 that is 360 px wide (640 × 9 / 16), only 230,400 pixels against 8,294,400 at the recommended size, 2.8% of them. Treat 640 px as the minimum, not a target; the recommended 2160 × 3840 px has far more pixels to work with.
Free tools:YouTube video thumbnail sizeYouTube community post image size
Frequently asked questions
What size is a YouTube Shorts thumbnail?
2160 × 3840 px at 9:16, with a minimum height of 640 px, as JPG or PNG up to 50 MB from a computer, according to YouTube Help.
Can I add a custom Shorts thumbnail from my phone?
No. YouTube says custom Shorts thumbnails are currently only available to add in YouTube Studio on a computer, and your account must be verified.
Why does YouTube replace my custom thumbnail with a different one?
For vertical videos with a 16:9 custom thumbnail, YouTube uses an auto-generated 4:5 thumbnail on the home, explore and subscription pages.
What is the maximum file size for a Shorts thumbnail?
50 MB from a desktop, according to YouTube Help. The 2 MB limit on that page is for video thumbnails uploaded from mobile.
Is 1080 x 1920 accepted for a Shorts thumbnail?
YouTube's page names 2160 × 3840 px and a 640 px minimum height. A 1080 × 1920 px file is above the minimum, but the page does not name that size.
Other YouTube sizes
Sources
- YouTube Help: Add custom video thumbnails (checked 2026-10-07)