Checked on October 4, 2026, based on the YouTube Help articles "Add video thumbnails" and "Manage your channel branding".
Official specs from YouTube Help
| Item | Value |
|---|---|
| Aspect ratio | Videos 16:9, Shorts 9:16 |
| Minimum size | Videos 640px wide, Shorts 640px tall |
| Recommended resolution | As large as possible (up to 3840×2160 for videos and 2160×3840 for Shorts) |
| Format | JPG, PNG |
| File size | 2 MB when uploading from mobile, 50 MB from desktop |
Articles disagree on whether the limit is 2 MB or 50 MB because it depends on the device you upload from. If you might ever upload from your phone, keeping it under 2 MB means it will upload anywhere.
In practice, most people use 1280×720 or 1920×1080. Both are 16:9, so the ratio is the same; you can go bigger, but the file gets larger. 1280×720 also matches the resolution YouTube generates for video previews, which makes it the safest choice.
Why these specs?
YouTube shows the same video on devices with completely different screens: TVs, computers and phones. A fixed 16:9 ratio fills any screen without cropping the top, bottom or sides. The 640px minimum width exists for a similar reason: smaller images look fuzzy when they're scaled up on a big screen.
How to make one
- Open the YouTube Thumbnail Maker and a 1280×720 canvas is ready. No ratio math needed.
- Add a background photo and adjust its position and zoom so it fills the frame.
- Turn on the safe-area guide and check that no text or important face sits outside the safe area.
- Add a title in a bold font and separate it from the background with an outline or shadow.
- In Save, choose JPG, check that the file is under 2 MB, and download.
Where should the text go?
The video length is overlaid in the bottom-right corner of a video thumbnail, so keep text and faces out of that spot. The safe-area guide in the YouTube Thumbnail Maker shows the approximate position. The top left and center are relatively safe, but both edges can be slightly covered in mobile lists, so it's safest to keep key text within the central 70%.
A note on vertical videos
According to YouTube Help, vertical videos with a 16:9 custom thumbnail show an auto-generated 4:5 thumbnail instead on the Home, Explore and Subscriptions pages. If the video will be a Short, make a separate 9:16 canvas from the start.
Good vs. bad examples
| Good | Bad |
|---|---|
| One line of text, a few short words, bold font | Three or more lines of text, thin font |
| Strong contrast between background and text color | Background and text with similar brightness |
| Bottom-right corner (video length) left empty | Important numbers or faces covered |
| Image that matches the video's content | Exaggerated scene that isn't in the video |
Common problems
- The file is too large to upload. Save as JPG and lower the quality. The JPG auto-compress option in the thumbnail maker can target 2 MB for you.
- It says my account needs verification. Custom thumbnails can be uploaded after your account is verified.
- I want to save someone else's thumbnail. A thumbnail can be the uploader's copyrighted work. Saving, reusing, redistributing or using it commercially without permission can be copyright infringement and may also break YouTube's Terms of Service. Only do this for your own videos or ones you have permission for.
- I uploaded a thumbnail but it hasn't changed. It can take some time to show up everywhere.
Checklist before you make it
- Is the canvas 1280×720 (or another 16:9 size)?
- Did you save as JPG, and is it under 2 MB?
- Did you leave the bottom-right video-length spot empty?
- Is the text still readable when shrunk down?
- Does the image match what's actually in the video?
FAQ
Do I have to use exactly 1280×720?
No. You only need a 16:9 ratio and a minimum width of 640px. Still, 1280×720 is the most common size because it balances file size and quality well.
Should I use PNG or JPG?
For thumbnails with photos, JPG files are much smaller. For mostly text on a solid background, PNG can look sharper, but the file may get larger.
Do I need a separate thumbnail for Shorts?
Yes. Shorts need their own 9:16 ratio with a minimum height of 640px. A 16:9 thumbnail used as-is will show only the cropped center.