YouTube recommends 3840 × 2160 pixels for video thumbnails, in a 16:9 shape, at least 640 pixels wide. Use JPG or PNG. The file can weigh up to 2 MB from the phone app and 50 MB from a computer.
Thumbnail specs for videos and Shorts
| Videos | Shorts | |
|---|---|---|
| Recommended size | 3840 × 2160 pixels | 2160 × 3840 pixels |
| Minimum | 640 pixels wide | 640 pixels tall |
| Shape | 16:9 | 9:16 |
| Formats | JPG or PNG | JPG or PNG |
| Max file size | 2 MB (phone), 50 MB (computer) | 50 MB (computer) |
Source: YouTube Help, “Add video thumbnails”.
Is 1280 × 720 still the right size?
For years, 1280 × 720 pixels was the number everyone quoted. It still works: it is a 16:9 image and it is well above the 640 pixels minimum width. But YouTube Help now recommends 3840 × 2160 pixels, four times as many pixels in each direction.
A larger thumbnail looks sharper on big screens and TVs, and it gives you room to crop later. If your editing app or your computer struggles with very large files, 1920 × 1080 is a sensible middle ground. Whatever you pick, keep the 16:9 shape so the image fills the frame without bars.
Why your thumbnail looks blurry or cropped
- The shape is not 16:9. A square or 4:3 image gets cropped or padded. The checker above shows the exact ratio of your file.
- The image was enlarged. Scaling a small screenshot up to 1920 pixels adds blur. Start from a large source image instead.
- Text is too small. Most viewers see your thumbnail at phone size. If a word is hard to read in the smallest preview of the checker, it is too small.
- Something sits in the bottom-right corner. That is where the video length usually appears, so it hides part of your image.
How to upload a custom thumbnail
Custom thumbnails need a verified account: YouTube asks for phone verification before you can upload your own image. Once that is done, open the video in YouTube Studio, go to its details and choose your file in the thumbnail section. From the phone app, remember the lower 2 MB limit.
For Shorts, YouTube Help says custom thumbnails can currently be added only in YouTube Studio on a computer, and they use the vertical 9:16 shape.
Need to change the size of an image first? The thumbnail resizer exports a 16:9 or 9:16 file in your browser.
FAQ
What is the best size for a YouTube thumbnail?
3840 × 2160 pixels is the size YouTube recommends today. Any 16:9 image at least 640 pixels wide is accepted.
Can I use a PNG thumbnail?
Yes. YouTube Help lists JPG and PNG. A JPG is usually much lighter, which matters when you upload from your phone.
Why can’t I upload a custom thumbnail?
The usual reason is that the account is not verified yet. Verify your channel with a phone number, then try again.
What size is a Shorts thumbnail?
YouTube recommends 2160 × 3840 pixels in a 9:16 shape, at least 640 pixels tall. Switch the checker to “Shorts” to test a vertical image.